- Email: [email protected]
Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement?
ARTICLE IN PRESS
JID: YMSY
[m5G;April 21, 2018;16:2]
Surgery 0 0 0 (2018) 1–6
Contents lists available at ScienceDirect
Surgery journal homepage: www.elsevier.com/locate/surg
Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement?✩ Sameer A. Hirji, Masaki Funamoto, Jiyae Lee, Fernando Ramirez Del Val, Ahmed A. Kolkailah, Siobhan McGurk, Marc P. Pelletier, Sary Aranki, Prem S. Shekar, Tsuyoshi Kaneko∗ Division of Cardiac Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
a r t i c l e
i n f o
Article history: Accepted 22 February 2018 Available online xxx
a b s t r a c t Background: Minimally invasive aortic valve replacement using upper-hemisternotomy has been associated with improved results compared to full sternotomy aortic valve replacement. Given the likely expansion of transcatheter aortic valve replacement to low-risk patients, we examine contemporary outcomes after full sternotomy and minimally invasive aortic valve replacement in low-risk patients using our 15year experience. Methods: Two thousand ninety-five low-risk patients (Society of Thoracic Surgeons Predicted Risk of Mortality score <4) underwent elective isolated aortic valve replacement, including 1,029 (49%) minimally invasive and 1,066 (51%) full sternotomy, from 2002 to 2015. Results: Compared to minimally invasive aortic valve replacement patients, full sternotomy aortic valve replacement patients had a greater burden of comorbidities, including diabetes, stroke, congestive heart failure, and predicted risk of mortality (all P ≤ .05). Operative mortality, stroke, and reoperation rates for bleeding were similar. There was a clinical trend toward shorter median intensive care unit stay and significantly shorter hospital length of stay among minimally invasive aortic valve replacement patients. Adjusted survival analysis identified age, chronic kidney disease, prior sternotomy, and congestive heart failure as predictors of decreased survival (all P ≤ .05), while type of intervention approach was nonsignificantly different. Conclusion: In low-risk patients, minimally invasive aortic valve replacement results in similar mortality, stroke, reoperation rates for bleeding, and midterm survival (after adjusting for confounders), but shorter hospital length of stay and a trend (P = .075) toward shorter intensive care unit stay, compared to full sternotomy aortic valve replacement. Therefore, minimally invasive aortic valve replacement should stand as a benchmark against transcatheter aortic valve replacement in these patients. © 2018 Elsevier Inc. All rights reserved.
Introduction Operative aortic valve replacement (SAVR) is the traditional cornerstone of therapy for severe AS and leads to improvements in symptoms and survival.1 This well-established operation was challenged recently by the emergence of transcatheter aortic valve replacement (TAVR). TAVR showed comparable outcomes in inoperable and high-risk patients, which led to its approval by the US
✩ Presented at the 13th Annual Academic Surgical Congress/Society of University Surgeons, January 30, 2018, Jacksonville, FL ∗ Corresponding author: Division of Cardiac Surgery, Brigham and Women’s Hospital, 75 Francis St, Boston, MA 02115. E-mail address: [email protected] (T. Kaneko).
Food and Drug Administration.2-4 More recently, the Placement of Aortic Transcatheter Valves (PARTNER) 2A trial showed superiority of transfemoral TAVR over SAVR in the intermediate risk population.5,6 SAVR has also evolved over the years in the form of a minimally invasive approach via an upper sternotomy or a right minithoracotomy. Compared to aortic valve replacement (AVR) via a conventional full sternotomy (fAVR), minimally invasive AVR (mAVR) is associated with improved clinical outcomes and comparable shortand long-term survival, especially in high-risk elderly patients.7,8 For low-risk patients (Society of Thoracic Surgeons [STS]Predicted Risk of Mortality [PROM] score <4%), SAVR currently remains the mainstay treatment despite the increased interest in exploring the role of TAVR in this select cohort. In recent years, mAVR
https://doi.org/10.1016/j.surg.2018.02.018 0039-6060/© 2018 Elsevier Inc. All rights reserved.
Please cite this article as: S.A. Hirji et al., Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement? Surgery (2018), https://doi.org/10.1016/j.surg.2018.02.018
JID: YMSY 2
ARTICLE IN PRESS
[m5G;April 21, 2018;16:2]
S.A. Hirji et al. / Surgery 000 (2018) 1–6
has been appealing to both the surgeons and the patients, given its superior outcomes reported mostly in retrospective, singleinstitutional studies.7,8 While we await the results of 2 ongoing trials for low-risk patients (PARTNER 3 and CoreValve Evolut R trial), it is extremely crucial to understand how these contemporary operative approaches compare so that we can select the most efficient and safe approach for SAVR (ie, fAVR versus mAVR). These data will be extremely relevant and will help guide important clinical decisions in appropriate operative candidates, and hopefully will serve as a robust benchmark for comparison as TAVR technology evolves. Using our extensive, 15-year, single-center experience, we examined in-hospital outcomes and midterm survival in lowrisk patients undergoing isolated AVR using either full sternotomy (fAVR) or minimally invasive AVR (mAVR). Methods Patient demographics
Outcomes of interest Primary outcomes of interest were operative mortality and postoperative survival. Secondary outcomes included length of stay (LOS), incidence of permanent stroke, new onset renal failure, and reoperation for bleeding. We defined operative mortality as any death occurring in-hospital during the index admission or within 30 days postoperatively if discharged. The STS-PROM score was calculated using the 2008 algorithm. The observed-to-expected ratio (O/E ratio) was the percent operative mortality divided by the STS-PROM. Survival data was obtained from our internal research data repository, routine patient or clinic follow-up, patient surveys, query of the Social Security death index, and our state Department of Public Health Records. Follow-up time was calculated in months from the date of operation to the date of death or December 30, 2015 (ie, 6 months after the study period). There was 99% followup for patient survival. For patients lost to follow-up, observation time was censored at the point of last known clinical contact.
After approval by our institutional review board, we identified all adult patients who underwent an isolated AVR procedure either with a bi-leaflet mechanical or bioprosthetic valve (either stented or stentless) at our institution between January 2002 and June 2015. Only patients with a low STS risk scores (STS-PROM score <4%) were included. Patients younger than 18 years and those undergoing concurrent coronary artery bypass grafting (CABG), mitral or tricuspid valve replacements, ascending aorta or arch surgery, or placement of ventricular assist devices were excluded from the analysis. The decision to perform mAVR vs fAVR was at the discretion of the operating surgeon in concert with patient preference. While the choice of operative approach took into account many comorbidities, patients with obesity and greater anterior-posterior diameter were considered difficult candidates for mAVR. Reoperation or previous radiation was not an exclusion criterion for miniAVR.
Statistical analysis
Data collection
Results
Patient demographics and operative and in-hospital outcomes were extracted from our hospital electronic medical records and from our internal research data repository. All variables were coded to the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database version 2.52 specifications unless otherwise indicated. Chronic kidney disease (CKD) was defined a priori as a preoperative creatinine ≥2.0 mm/dL or most recent clinical documentation of renal disease. The decision to perform fAVR or mAVR was at the discretion of the primary surgeon and the patient at the time of implantation.
Patient demographics
Operative technique Our institution has utilized extensively the minimally invasive sternotomy approach and previously reported the operative technique.7,9 , 10 Briefly, mAVR involves an upper hemisternotomy approach in which a 6- to 9-cm skin incision is made and the sternum is transected horizontally at the level of the 4th intercostal space, taking care to avoid injury to the right internal mammary artery.7,9 The patient is fully heparinized, and the ascending aorta is assessed for safe cannulation with an aid of epiaortic ultrasonography. Cardiopulmonary bypass is then initiated with ascending aortic cannulation for arterial return and right atrial cannulation for venous drainage. Antegrade cardioplegia is given and, if greater than mild aortic insufficiency is present, aortotomy is performed for direct ostial delivery. Retrograde cardioplegia is also given via cannulation of the right atrium to ensure normothermic cardiopulmonary bypass.
Normally distributed variables were expressed as a mean with standard deviation and compared using Student’s t-tests with Levene’s test for homogeneity for variance. Non-normally distributed variables were expressed as a median with interquartile range (IQR) and were compared using the Mann-Whitney U tests. Categorical variables were presented as number and percentages and were compared using χ 2 or Fisher’s exact tests. Adjusted survival was evaluated using Cox proportional hazard modeling. Variables selected included those found to be significantly different between groups on univariate analyses, variables known to be contributors to postoperative mortality, and those deemed clinically meaningful in the context of an AVR. All analyses were conducted using IBM SPSS Statistics version 23.0 (IBM Corporation, Armonk, NY) with P ≤ .05 as the criterion for significance.
Our cohort consisted of 2,095 patients who underwent an isolated AVR, including 1,066 fAVR patients (51%) and 1,029 mAVR patients (49%). Overall, the mean age was 65.6 years, which included 33.6% women (705). As demonstrated by the low overall STS-PROM score (1.85), the preoperative incidence of comorbidities, such as diabetes (17.0%), CKD (1.3%), previous cerebrovascular accident (CVA) (3.3%), and previous myocardial infarction (MI) (5.9%) were low. Compared to mAVR patients, fAVR patients had a greater STS-PROM score (1.91 vs 1.81), and a significantly greater burden of comorbidities, such as diabetes (22.7% vs 11.1%), previous stroke (4.1% vs 2.4%), congestive heart failure (CHF) (40.9% vs 23.6%), and New York Heart Association class III/IV (31.1% vs. 25.8%; all P ≤ .05). mAVR was performed more likely in patients age ≥80 years (15.5% vs 10.9%), while fAVR was more frequently used in morbidly obese patients (body mass index ≥40, 9.1% vs 2.4%; all P < .001). Baseline patient characteristics were otherwise similar between the 2 groups, as demonstrated in Table 1. Median follow-up time was 5.3 years (IQR 2.5, 8.5, range 0 to 13 years) with 11,935 patient-years of data. Operative and in-hospital outcomes Compared to fAVR patients, mAVR patients had less perfusion times (81 vs 100 minutes) and cross clamp times (62 vs 69 minutes; all P < .001, Table 2). mAVR patients also had greater preoperative aortic valve gradients (47 vs 42.2 mmHg) and were less
Please cite this article as: S.A. Hirji et al., Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement? Surgery (2018), https://doi.org/10.1016/j.surg.2018.02.018
ARTICLE IN PRESS
JID: YMSY
[m5G;April 21, 2018;16:2]
S.A. Hirji et al. / Surgery 000 (2018) 1–6
3
Table 1 Baseline patient characteristics between fAVR and mAVR All n = 2,095 Age, y Age ≥80 y Women BMI BMI ≥40 Chronic kidney disease Preop creatinine (mg/dL) Diabetes Hypertension Dyslipidemia Peripheral vascular disease Cerebrovascular disease Previous stroke Previous MI Ejection fraction (%) CHF <2 weeks NYHA Class III/IV Preop mean valve gradient STS PROM
65.6 275 705 29.1 122 26 0.99 356 1666 1387 117 175 68 124 60 679 597 45.47 1.85
fAVR n = 1,066 (12.9) (13.1) (33.6) (7.2) (5.8) (1.3) (0.43) (17.0) (79.5) (66.2) (5.6) (8.3) (3.3) (5.9) (55, 65) (32.4) (28.5) (16.33) (0.97)
65.8 116 407 30.5 97 16 0.99 242 848 734 70 113 44 72 60 436 332 42.20 1.91
P≤
mAVR n = 1,029 (12.8) (10.9) (38.2) (8.4) (9.1) (1.5) (0.27) (22.7) (79.5) (68.9) (6.6) (10.6) (4.1) (6.8) (55, 65) (40.9) (31.1) (20.10) (0.95)
65.4 159 297 27.7 25 10 0.99 114 818 652 46 62 25 51 60 243 265 47.00 1.80
(13.0) (15.5) (28.9) (5.4) (2.4) (1.0) (0.56) (11.1) (79.5) (63.4) (4.5) (6.0) (2.4) (5.0) (55, 65) (23.6) (25.8) (20.20) (0.98)
.426 .002 .753 .001 .001 .326 .965 .001 1.0 0 0 .008 .044 .001 .037 .078 .001 .001 .007 .001 .009
∗
Continuous variables are presented as mean (SD) unless otherwise noted as median (IQR); categorical variables are summarized as n (%). BMI, body mass index; NYHA, New York Heart Association. Table 2 Operative characteristics and in-hospital outcomes All n = 2,095
fAVR n = 1,066
mAVR n = 1,029
P≤
Operative details Previous cardiac surgery Emergent status Perfusion time (min) Cross clamp time (min)
216 3 97 70
(10.3) (0.2) (79, 123) (57, 90)
165 2 100 69
(15.5) (0.2) (81, 126) (56, 85)
50 1 81 62
(4.9) (0.1) (46, 126) (14, 62)
.001 1.0 0 0 .001 .001
In-hospital outcomes Reoperation for bleeding Valve reoperation
35 3
(1.7) (0.2)
14 3
(1.3) (0.3)
22 0
(2.1) (0.0)
48 20 39
(2.3) (1.0) (24, 65)
27 19 51
(2.5) (1.8) (28, 76)
22 1 31
(2.1) (0.9) (23, 61)
.179 .250 .2 .504 .086 .075
6.0 0 25
(5, 8)
7
(6, 8)
6
(5, 7)
.001
(1.2) 0.648
12
(1.1) 0.576
13
(1.3) 0.722
.636
Permanent stroke New onset renal failure ICU stay (h) IC Postop LOS (days) Operative mortality O/E ratio ∗
Continuous variables are presented as mean (SD) unless otherwise noted as median (IQR); categorical variables are summarized as n (%).
likely to have undergone previous cardiac surgery (4.9% vs 15.5%; all P < .05). There were no differences in operative mortality (1.1% vs 1.3%), stroke (3% vs 2%), reoperation rates for bleeding (1% vs 2%), and repeated valve procedures (0% vs 0.3%; all P > .05) among fAVR and mAVR patients, respectively. Likewise, mAVR patients also had less STS-predicted mortality (1.8 ± 0.98 vs 1.9 ± 0.95; P = .009) resulting in an O/E ratio of 0.722 vs 0.574. There was a clinical trend toward less median ICU stays (31 vs 51 hours; P = .075) for mAVR compared to fAVR patients, respectively. The hospital LOS was 1 day less in the mAVR patients (6 vs 7 days; P ≤ .001).
cohorts (Fig. 2). The Cox proportional hazard modeling identified CKD (hazard ratio [HR] 2.74, 95% confidence interval [CI]: 1.295.81), CHF (HR 1.84, 95% CI: 1.43-2.36), previous cardiac surgery (HR 1.53, 95% CI: 1.08-2.18), New York Heart Association class III/IV (HR 1.29, 95% CI: 1.00-1.68), and age (per year >65) (HR 1.04, 95% CI: 1.04-1.06) as contributors to decreased postoperative survival (Table 3). Variables that were noncontributory included operative (sternotomy) approach (P = .799), sex, CVA, cerebrovascular disease, peripheral vascular disease, emergent status, ejection fraction (%), hypertension, hypercholesterolemia, and diabetes. Discussion
Mid-term survival During the study period, 266 deaths were observed. Temporal differences in the number of procedures during the study period are highlighted in Fig. 1. mAVR patients had a greater unadjusted survival compared to fAVR patients, with mean survival times of 12.5 years and 11.9 years, respectively (P ≤ .025), but there was no difference in cumulative adjusted survival between the 2 patient
Establishing a benchmark operative approach for SAVR is extremely relevant in low-risk patients requiring an AVR, particularly in the current era of explosion in TAVR. We used our extensive, 15year, single-center experience to compare outcomes of fAVR and mAVR to help guide important clinical decisions. This large study has several noteworthy findings. We have demonstrated that mAVR and fAVR patients had similar operative mortality and in-hospital
Please cite this article as: S.A. Hirji et al., Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement? Surgery (2018), https://doi.org/10.1016/j.surg.2018.02.018
ARTICLE IN PRESS
JID: YMSY 4
[m5G;April 21, 2018;16:2]
S.A. Hirji et al. / Surgery 000 (2018) 1–6
Fig. 1. Temporal trends of fAVR and mAVR procedures in low-risk patients between 2002 and 2016.
Table 3 Cox proportional hazard modeling 95.0% CI Contributing factors
P≤
HR
Lower
Upper
CHF ≤2 weeks Age (per year >65) CKD Previous cardiac surgery NYHA class III/IV
.001 .001 .009 .016 .050
1.837 1.048 2.737 1.534 1.294
1.432 1.036 1.290 1.082 1.0 0 0
2.358 1.060 5.809 2.176 1.676
There were 266 deaths during observation period. Residual χ 2 = 7.352, P = .069. Noncontributory variables include sternotomy type (ie, mAVR versus fAVR), sex, cerebrovascular accident, peripheral vascular disease, emergent procedure, ejection fraction (%), hypertension, diabetes, and hypercholesterolemia. NYHA, New York Heart Association.
outcomes, such as stroke, reoperation rates for bleeding, and repeat valve procedures. Even after adjusting for various patientrelated factors, mAVR and fAVR patients had similar midterm survival; mAVR did, however, tend to result in a shorter hospital LOS and a shorter ICU stay. Given the high stakes against TAVR, this shorter LOS in the hospital and the ICU suggests that mAVR should stand as a benchmark against TAVR in low-risk patients. Given the changing landscape in patient profile and extent of comorbidities, there has been considerable interest and growth in TAVR. TAVR is a less invasive and less morbid approach to AVR that has been studied recently in comparison to medical therapy and to SAVR in patients with AS. The initial studies of TAVR enrolled inoperable and high-risk patients as defined by their STSPROM scores. In inoperable patients, TAVR compared to medical
therapy led to improved survival (69.3% vs 49.3%), a decreased rate of repeat hospitalization (22.3% vs 44.1%), and a decrease in cardiac symptoms (25.2% vs 58% at 1 year; all P < .05).11 In highrisk patients, TAVR compared to SAVR lead to a somewhat improved survival at 1 year (75.8% vs 73.2%; P = .44).2 More recently, the PARTNER 2 trial explored the feasibility and utility of TAVR in intermediate-risk patients and demonstrated similar rates of mortality (16.7% vs 18%), repeat hospitalization (19.6% vs 17.3%; P = .22) and stroke (6.2% vs 6.4%) compared to SAVR at 2 years (all P > .05).6 As a result, the US Food and Drug Administration (FDA) approved TAVR for intermediate-risk patients in addition to high-risk patients on the basis of these recent trials.12 Furthermore, current clinical practice guidelines of the American College of Cardiology/American Heart Association (ACC/AHA) and the European Society of Cardiology (ESC) recommend TAVR for treatment of severe AS in patients who are inoperable or at high risk for classic operative AVR.13,14 Recently, the ACC added TAVR as a grade IIa recommendation in AS patients with an intermediate operative risk.15 With the early success of existing efforts, the population eligible for TAVR has continued to expand, with clinicians now advocating for use of TAVR in low-risk patients. A recent randomized trial, the Nordic Aortic Valve Intervention Trial (NOTION), demonstrated that in low-surgical-risk patients with an average STS risk score of 3% TAVR achieved noninferiority compared to SAVR for the primary end-point of mortality or stroke at 1 year16 ; however, this study randomized only 18% of the screened patients, which likely limited its power. Currently, at least 2 major randomized controlled trials, the PARTNER 3 trial (NCT02675114) and The CoreValve Evolut R Low-Risk trial (NCT02701283), are randomizing low-risk patients to SAVR or TAVR. Although currently intermediate-risk
Please cite this article as: S.A. Hirji et al., Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement? Surgery (2018), https://doi.org/10.1016/j.surg.2018.02.018
JID: YMSY
ARTICLE IN PRESS
[m5G;April 21, 2018;16:2]
S.A. Hirji et al. / Surgery 000 (2018) 1–6
5
Fig. 2. Adjusted Cox proportional hazards survival curves for low-risk fAVR and mAVR patients.
patients include those with STS scores of 3 to 8, the PARTNER 2 trial classified intermediate patients with STS scores of 4 to 8. These 2 ongoing trials also have different cut-offs for low-risk. For example, the PARTNER 3 trial uses the <4% low-risk cut-off, while the CoreValve Evolut R Low-risk trial uses <3% as its study cut-off. For these reasons, we chose STS scores <4% as the cut-off, so that our results would be comparable to both these trials. While we await the results of these 2 trials (which will take time to complete), it is essential and very timely to understand contemporary outcomes of the conventional fAVR and the minimally invasive approach (mAVR). In recent years, minimally invasive aortic surgery has become established as an accepted approach to conventional sternotomy (fAVR) in the operative management of aortic disease, although this technique is limited to selected cardiac surgery centers, and in centers without TAVR availability. Compared to fAVR, mAVR is associated with improved clinical outcomes, especially in high-risk elderly patients. Our institution published our experience previously on 552 matched pairs comparing mAVR versus fAVR over a 10-year period, and found that mAVR patients had less ventilation times, shorter ICU stays, and shorter LOS, but no observed differences in short- or long-term survival or need for operative re-intervention.7 In a systematic review and meta-analysis of 26 studies and 4,546 patients undergoing AVR by Brown et al, mAVR was associated with shorter ICU and hospital LOS, less ventilation
times, and less blood loss within 24 hours, despite no difference in mortality.17 Similarly, Semsroth et al compared 118 matched pairs of mAVR and fAVR from 2005 to 2013 and found no significant differences in perioperative outcomes or 1-year survival, although a trend of better survival was observed with mAVR.18 These findings are consistent with our results. Importantly, several studies have also shown that mAVR results in improved patient satisfaction, decreased postoperative pain and narcotic use, improved cosmesis, faster recovery of respiratory function, and an earlier hospital discharge compared to fAVR.17 , 19-21 While TAVR is promising because it also seems to offer a clear advantage in terms of a decrease in acute kidney injury and need of blood transfusion, TAVR is associated with a greater risk of permanent pacemaker implantation (PPI), moderate-to-severe paravalvular regurgitation (PVL), and vascular complications.22 In addition, limited long-term data on durability of the TAVR valve raises concern. Daubert et al recently examined long-term performance of TAVR valves in terms of hemodynamic and valvular profile among patients who were enrolled previously in the PARTNER I trial and found no change in AV area or in total transvalvular or paravalvular aortic regurgitation over 5 years.23 Despite these results suggesting that valve performance and cardiac hemodynamics are stable after implantation of TAVR valves, valve durability is still unknown and has to be cautiously indicated in the young low-risk population.
Please cite this article as: S.A. Hirji et al., Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement? Surgery (2018), https://doi.org/10.1016/j.surg.2018.02.018
JID: YMSY 6
ARTICLE IN PRESS
[m5G;April 21, 2018;16:2]
S.A. Hirji et al. / Surgery 000 (2018) 1–6
Although this study had many merits, including our large sample size and robust clinical follow-up, it also has several limitations. First, our study was limited by its observational, singlecenter, nonrandomized nature. Moreover, there may be patient selection biases and other inherent confounders which could have affected the study results, although we attempted to adjust for several confounders. Second, the study lacked preoperative and postoperative echocardiographic data because many cases either were performed prior to the mandated STS reporting guidelines on data reporting or were referred from outside, nontertiary centers. Thus, accurate data assessment of hemodynamic performance of valves is limited. Third, common criteria outside of STS such as patient frailty and other comorbidities such as cirrhosis not captured by the STS score were not available. Fourth, our median follow-up was 5.3 years, which may have limited our ability to see any survival differences in a longer time period in this population. Despite its advantage, mAVR has not been used recently in part because of substantial physician turnover in our practice. We had several new faculty members who joined our institution and do not perform mAVR routinely, which explains the odd trend. Despite this, our results did not change by adding 2016 data. Using our extensive, 15-year, single-center experience, this study provides a robust benchmark for comparison of TAVR in lowrisk patients (STS score <4%). In these patients, mAVR results in shorter ICU and hospital LOS, while maintaining a similar rate of mortality, stroke, reoperation for bleeding, and mid-term survival compared to fAVR. With increasing patient preference for less invasive approaches and need for early recovery, mAVR should stand as a benchmark against TAVR in low-risk patients. References 1. Potter DD, Sundt 3rd TM, Zehr KJ, Dearani JA, Daly RC, Mullany CJ, et al. Operative risk of reoperative aortic valve replacement. J Thorac Cardiovasc Surg. 2005;129:94–103. 2. Smith CR, Leon MB, Mack MJ, Miller DC, Moses JW, Svensson LG, et al. Transcatheter versus surgical aortic-valve replacement in high-risk patients. N Engl J Med. 2011;364:2187–2198. 3. Leon MB, Smith CR, Mack M, Miller DC, Moses JW, Svensson LG, et al. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med. 2010;363:1597–1607. 4. Makkar RR, Fontana GP, Jilaihawi H, Kapadia S, Pichard AD, Douglas PS, et al. Transcatheter aortic-valve replacement for inoperable severe aortic stenosis. N Engl J Med. 2012;366:1696–1704. 5. Thourani VH, Kodali S, Makkar RR, Herrmann HC, Williams M, Babaliaros V, et al. Transcatheter aortic valve replacement versus surgical valve replacement in intermediate-risk patients: a propensity score analysis. Lancet. 2016;387:2218–2225. 6. Leon MB, Smith CR, Mack MJ, Makkar RR, Svensson LG, Kodali SK, et al. Transcatheter or Surgical Aortic-Valve Replacement in Intermediate-Risk Patients. N Engl J Med. 2016;374:1609–1620.
7. Neely RC, Boskovski MT, Gosev I, Kaneko T, McGurk S, Leacche M, et al. Minimally invasive aortic valve replacement versus aortic valve replacement through full sternotomy: the Brigham and Women’s Hospital experience. Ann Cardiothorac Surg. 2015;4:38–48. 8. Kaneko T, Loberman D, Gosev I, Rassam F, McGurk S, Leacche M, et al. Reoperative aortic valve replacement in the octogenarians-minimally invasive technique in the era of transcatheter valve replacement. J Thorac Cardiovasc Surg. 2014;147:155–162. 9. Gosev I, Neely RC, Leacche M, McGurk S, Kaneko T, Zeljko D, et al. The impact of a minimally invasive approach on reoperative aortic valve replacement. J Heart Valve Dis. 2015;24:181–186. 10. Gosev I, Kaneko T, McGurk S, McClure SR, Maloney A, Cohn LH. A 16-year experience in minimally invasive aortic valve replacement: context for the changing management of aortic valve disease. Innovations. 2014;9:104–110 discussion 110. 11. Leon MB, Smith CR, Mack M, Miller DC, Moses JW, Svensson LG, et al. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med. 2010;363:1597–1607. 12. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin 3rd JP, Guyton RA, et al. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;63:2438–2488. 13. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin 3rd JP, Guyton RA, et al. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;63:e57–185. 14. Vahanian A, Alfieri O, Andreotti F, Antunes MJ, Baron-Esquivias G, Baumgartner H, et al. [Guidelines on the management of valvular heart disease (version 2012). The Joint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS)]. G Ital Cardiol (Rome). 2013;14:167–214. 15. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin 3rd JP, Fleisher LA, et al. 2017 AHA/ACC Focused Update of the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. 2017. 16. Thyregod HG, Sondergaard L, Ihlemann N, Franzen O, Andersen LW, Hansen PB, et al. The Nordic aortic valve intervention (NOTION) trial comparing transcatheter versus surgical valve implantation: study protocol for a randomised controlled trial. Trials. 2013;14:11. 17. Brown ML, McKellar SH, Sundt TM, Schaff HV. Ministernotomy versus conventional sternotomy for aortic valve replacement: a systematic review and meta– analysis. J Thorac Cardiovasc Surg. 2009;137:670–679 e5. 18. Semsroth S, Matteucci Gothe R, Raith YR, de Brabandere K, Hanspeter E, Kilo J, et al. Comparison of Two Minimally Invasive Techniques and Median Sternotomy in Aortic Valve Replacement. Ann Thorac Surg. 2017;104:877–883. 19. Cohn LH. Minimally invasive aortic valve surgery: technical considerations and results with the parasternal approach. J Cardiac Surg. 1998;13:302–305. 20. Cohn LH, Adams DH, Couper GS, Bichell DP, Rosborough DM, Sears SP, et al. Minimally invasive cardiac valve surgery improves patient satisfaction while reducing costs of cardiac valve replacement and repair. Ann Surg. 1997;226:421–426 discussion 427-8. 21. Malaisrie SC, Barnhart GR, Farivar RS, Mehall J, Hummel B, Rodriguez E, et al. Current era minimally invasive aortic valve replacement: techniques and practice. J Thorac Cardiovasc Surg. 2014;147:6–14. 22. Elmaraezy A, Ismail A, Abushouk AI, Eltoomy M, Saad S, Negida A, et al. Efficacy and safety of transcatheter aortic valve replacement in aortic stenosis patients at low to moderate surgical risk: a comprehensive meta-analysis. BMC Cardiovasc Disord. 2017;17:234. 23. Daubert MA, Weissman NJ, Hahn RT, Pibarot P, Parvataneni R, Mack MJ, et al. Long-Term Valve Performance of TAVR and SAVR: A Report From the PARTNER I Trial. JACC Cardiovasc Imag. 2016.
Please cite this article as: S.A. Hirji et al., Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement? Surgery (2018), https://doi.org/10.1016/j.surg.2018.02.018
JID: YMSY
[m5G;April 21, 2018;16:2]
Surgery 0 0 0 (2018) 1–6
Contents lists available at ScienceDirect
Surgery journal homepage: www.elsevier.com/locate/surg
Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement?✩ Sameer A. Hirji, Masaki Funamoto, Jiyae Lee, Fernando Ramirez Del Val, Ahmed A. Kolkailah, Siobhan McGurk, Marc P. Pelletier, Sary Aranki, Prem S. Shekar, Tsuyoshi Kaneko∗ Division of Cardiac Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
a r t i c l e
i n f o
Article history: Accepted 22 February 2018 Available online xxx
a b s t r a c t Background: Minimally invasive aortic valve replacement using upper-hemisternotomy has been associated with improved results compared to full sternotomy aortic valve replacement. Given the likely expansion of transcatheter aortic valve replacement to low-risk patients, we examine contemporary outcomes after full sternotomy and minimally invasive aortic valve replacement in low-risk patients using our 15year experience. Methods: Two thousand ninety-five low-risk patients (Society of Thoracic Surgeons Predicted Risk of Mortality score <4) underwent elective isolated aortic valve replacement, including 1,029 (49%) minimally invasive and 1,066 (51%) full sternotomy, from 2002 to 2015. Results: Compared to minimally invasive aortic valve replacement patients, full sternotomy aortic valve replacement patients had a greater burden of comorbidities, including diabetes, stroke, congestive heart failure, and predicted risk of mortality (all P ≤ .05). Operative mortality, stroke, and reoperation rates for bleeding were similar. There was a clinical trend toward shorter median intensive care unit stay and significantly shorter hospital length of stay among minimally invasive aortic valve replacement patients. Adjusted survival analysis identified age, chronic kidney disease, prior sternotomy, and congestive heart failure as predictors of decreased survival (all P ≤ .05), while type of intervention approach was nonsignificantly different. Conclusion: In low-risk patients, minimally invasive aortic valve replacement results in similar mortality, stroke, reoperation rates for bleeding, and midterm survival (after adjusting for confounders), but shorter hospital length of stay and a trend (P = .075) toward shorter intensive care unit stay, compared to full sternotomy aortic valve replacement. Therefore, minimally invasive aortic valve replacement should stand as a benchmark against transcatheter aortic valve replacement in these patients. © 2018 Elsevier Inc. All rights reserved.
Introduction Operative aortic valve replacement (SAVR) is the traditional cornerstone of therapy for severe AS and leads to improvements in symptoms and survival.1 This well-established operation was challenged recently by the emergence of transcatheter aortic valve replacement (TAVR). TAVR showed comparable outcomes in inoperable and high-risk patients, which led to its approval by the US
✩ Presented at the 13th Annual Academic Surgical Congress/Society of University Surgeons, January 30, 2018, Jacksonville, FL ∗ Corresponding author: Division of Cardiac Surgery, Brigham and Women’s Hospital, 75 Francis St, Boston, MA 02115. E-mail address: [email protected] (T. Kaneko).
Food and Drug Administration.2-4 More recently, the Placement of Aortic Transcatheter Valves (PARTNER) 2A trial showed superiority of transfemoral TAVR over SAVR in the intermediate risk population.5,6 SAVR has also evolved over the years in the form of a minimally invasive approach via an upper sternotomy or a right minithoracotomy. Compared to aortic valve replacement (AVR) via a conventional full sternotomy (fAVR), minimally invasive AVR (mAVR) is associated with improved clinical outcomes and comparable shortand long-term survival, especially in high-risk elderly patients.7,8 For low-risk patients (Society of Thoracic Surgeons [STS]Predicted Risk of Mortality [PROM] score <4%), SAVR currently remains the mainstay treatment despite the increased interest in exploring the role of TAVR in this select cohort. In recent years, mAVR
https://doi.org/10.1016/j.surg.2018.02.018 0039-6060/© 2018 Elsevier Inc. All rights reserved.
Please cite this article as: S.A. Hirji et al., Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement? Surgery (2018), https://doi.org/10.1016/j.surg.2018.02.018
JID: YMSY 2
ARTICLE IN PRESS
[m5G;April 21, 2018;16:2]
S.A. Hirji et al. / Surgery 000 (2018) 1–6
has been appealing to both the surgeons and the patients, given its superior outcomes reported mostly in retrospective, singleinstitutional studies.7,8 While we await the results of 2 ongoing trials for low-risk patients (PARTNER 3 and CoreValve Evolut R trial), it is extremely crucial to understand how these contemporary operative approaches compare so that we can select the most efficient and safe approach for SAVR (ie, fAVR versus mAVR). These data will be extremely relevant and will help guide important clinical decisions in appropriate operative candidates, and hopefully will serve as a robust benchmark for comparison as TAVR technology evolves. Using our extensive, 15-year, single-center experience, we examined in-hospital outcomes and midterm survival in lowrisk patients undergoing isolated AVR using either full sternotomy (fAVR) or minimally invasive AVR (mAVR). Methods Patient demographics
Outcomes of interest Primary outcomes of interest were operative mortality and postoperative survival. Secondary outcomes included length of stay (LOS), incidence of permanent stroke, new onset renal failure, and reoperation for bleeding. We defined operative mortality as any death occurring in-hospital during the index admission or within 30 days postoperatively if discharged. The STS-PROM score was calculated using the 2008 algorithm. The observed-to-expected ratio (O/E ratio) was the percent operative mortality divided by the STS-PROM. Survival data was obtained from our internal research data repository, routine patient or clinic follow-up, patient surveys, query of the Social Security death index, and our state Department of Public Health Records. Follow-up time was calculated in months from the date of operation to the date of death or December 30, 2015 (ie, 6 months after the study period). There was 99% followup for patient survival. For patients lost to follow-up, observation time was censored at the point of last known clinical contact.
After approval by our institutional review board, we identified all adult patients who underwent an isolated AVR procedure either with a bi-leaflet mechanical or bioprosthetic valve (either stented or stentless) at our institution between January 2002 and June 2015. Only patients with a low STS risk scores (STS-PROM score <4%) were included. Patients younger than 18 years and those undergoing concurrent coronary artery bypass grafting (CABG), mitral or tricuspid valve replacements, ascending aorta or arch surgery, or placement of ventricular assist devices were excluded from the analysis. The decision to perform mAVR vs fAVR was at the discretion of the operating surgeon in concert with patient preference. While the choice of operative approach took into account many comorbidities, patients with obesity and greater anterior-posterior diameter were considered difficult candidates for mAVR. Reoperation or previous radiation was not an exclusion criterion for miniAVR.
Statistical analysis
Data collection
Results
Patient demographics and operative and in-hospital outcomes were extracted from our hospital electronic medical records and from our internal research data repository. All variables were coded to the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database version 2.52 specifications unless otherwise indicated. Chronic kidney disease (CKD) was defined a priori as a preoperative creatinine ≥2.0 mm/dL or most recent clinical documentation of renal disease. The decision to perform fAVR or mAVR was at the discretion of the primary surgeon and the patient at the time of implantation.
Patient demographics
Operative technique Our institution has utilized extensively the minimally invasive sternotomy approach and previously reported the operative technique.7,9 , 10 Briefly, mAVR involves an upper hemisternotomy approach in which a 6- to 9-cm skin incision is made and the sternum is transected horizontally at the level of the 4th intercostal space, taking care to avoid injury to the right internal mammary artery.7,9 The patient is fully heparinized, and the ascending aorta is assessed for safe cannulation with an aid of epiaortic ultrasonography. Cardiopulmonary bypass is then initiated with ascending aortic cannulation for arterial return and right atrial cannulation for venous drainage. Antegrade cardioplegia is given and, if greater than mild aortic insufficiency is present, aortotomy is performed for direct ostial delivery. Retrograde cardioplegia is also given via cannulation of the right atrium to ensure normothermic cardiopulmonary bypass.
Normally distributed variables were expressed as a mean with standard deviation and compared using Student’s t-tests with Levene’s test for homogeneity for variance. Non-normally distributed variables were expressed as a median with interquartile range (IQR) and were compared using the Mann-Whitney U tests. Categorical variables were presented as number and percentages and were compared using χ 2 or Fisher’s exact tests. Adjusted survival was evaluated using Cox proportional hazard modeling. Variables selected included those found to be significantly different between groups on univariate analyses, variables known to be contributors to postoperative mortality, and those deemed clinically meaningful in the context of an AVR. All analyses were conducted using IBM SPSS Statistics version 23.0 (IBM Corporation, Armonk, NY) with P ≤ .05 as the criterion for significance.
Our cohort consisted of 2,095 patients who underwent an isolated AVR, including 1,066 fAVR patients (51%) and 1,029 mAVR patients (49%). Overall, the mean age was 65.6 years, which included 33.6% women (705). As demonstrated by the low overall STS-PROM score (1.85), the preoperative incidence of comorbidities, such as diabetes (17.0%), CKD (1.3%), previous cerebrovascular accident (CVA) (3.3%), and previous myocardial infarction (MI) (5.9%) were low. Compared to mAVR patients, fAVR patients had a greater STS-PROM score (1.91 vs 1.81), and a significantly greater burden of comorbidities, such as diabetes (22.7% vs 11.1%), previous stroke (4.1% vs 2.4%), congestive heart failure (CHF) (40.9% vs 23.6%), and New York Heart Association class III/IV (31.1% vs. 25.8%; all P ≤ .05). mAVR was performed more likely in patients age ≥80 years (15.5% vs 10.9%), while fAVR was more frequently used in morbidly obese patients (body mass index ≥40, 9.1% vs 2.4%; all P < .001). Baseline patient characteristics were otherwise similar between the 2 groups, as demonstrated in Table 1. Median follow-up time was 5.3 years (IQR 2.5, 8.5, range 0 to 13 years) with 11,935 patient-years of data. Operative and in-hospital outcomes Compared to fAVR patients, mAVR patients had less perfusion times (81 vs 100 minutes) and cross clamp times (62 vs 69 minutes; all P < .001, Table 2). mAVR patients also had greater preoperative aortic valve gradients (47 vs 42.2 mmHg) and were less
Please cite this article as: S.A. Hirji et al., Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement? Surgery (2018), https://doi.org/10.1016/j.surg.2018.02.018
ARTICLE IN PRESS
JID: YMSY
[m5G;April 21, 2018;16:2]
S.A. Hirji et al. / Surgery 000 (2018) 1–6
3
Table 1 Baseline patient characteristics between fAVR and mAVR All n = 2,095 Age, y Age ≥80 y Women BMI BMI ≥40 Chronic kidney disease Preop creatinine (mg/dL) Diabetes Hypertension Dyslipidemia Peripheral vascular disease Cerebrovascular disease Previous stroke Previous MI Ejection fraction (%) CHF <2 weeks NYHA Class III/IV Preop mean valve gradient STS PROM
65.6 275 705 29.1 122 26 0.99 356 1666 1387 117 175 68 124 60 679 597 45.47 1.85
fAVR n = 1,066 (12.9) (13.1) (33.6) (7.2) (5.8) (1.3) (0.43) (17.0) (79.5) (66.2) (5.6) (8.3) (3.3) (5.9) (55, 65) (32.4) (28.5) (16.33) (0.97)
65.8 116 407 30.5 97 16 0.99 242 848 734 70 113 44 72 60 436 332 42.20 1.91
P≤
mAVR n = 1,029 (12.8) (10.9) (38.2) (8.4) (9.1) (1.5) (0.27) (22.7) (79.5) (68.9) (6.6) (10.6) (4.1) (6.8) (55, 65) (40.9) (31.1) (20.10) (0.95)
65.4 159 297 27.7 25 10 0.99 114 818 652 46 62 25 51 60 243 265 47.00 1.80
(13.0) (15.5) (28.9) (5.4) (2.4) (1.0) (0.56) (11.1) (79.5) (63.4) (4.5) (6.0) (2.4) (5.0) (55, 65) (23.6) (25.8) (20.20) (0.98)
.426 .002 .753 .001 .001 .326 .965 .001 1.0 0 0 .008 .044 .001 .037 .078 .001 .001 .007 .001 .009
∗
Continuous variables are presented as mean (SD) unless otherwise noted as median (IQR); categorical variables are summarized as n (%). BMI, body mass index; NYHA, New York Heart Association. Table 2 Operative characteristics and in-hospital outcomes All n = 2,095
fAVR n = 1,066
mAVR n = 1,029
P≤
Operative details Previous cardiac surgery Emergent status Perfusion time (min) Cross clamp time (min)
216 3 97 70
(10.3) (0.2) (79, 123) (57, 90)
165 2 100 69
(15.5) (0.2) (81, 126) (56, 85)
50 1 81 62
(4.9) (0.1) (46, 126) (14, 62)
.001 1.0 0 0 .001 .001
In-hospital outcomes Reoperation for bleeding Valve reoperation
35 3
(1.7) (0.2)
14 3
(1.3) (0.3)
22 0
(2.1) (0.0)
48 20 39
(2.3) (1.0) (24, 65)
27 19 51
(2.5) (1.8) (28, 76)
22 1 31
(2.1) (0.9) (23, 61)
.179 .250 .2 .504 .086 .075
6.0 0 25
(5, 8)
7
(6, 8)
6
(5, 7)
.001
(1.2) 0.648
12
(1.1) 0.576
13
(1.3) 0.722
.636
Permanent stroke New onset renal failure ICU stay (h) IC Postop LOS (days) Operative mortality O/E ratio ∗
Continuous variables are presented as mean (SD) unless otherwise noted as median (IQR); categorical variables are summarized as n (%).
likely to have undergone previous cardiac surgery (4.9% vs 15.5%; all P < .05). There were no differences in operative mortality (1.1% vs 1.3%), stroke (3% vs 2%), reoperation rates for bleeding (1% vs 2%), and repeated valve procedures (0% vs 0.3%; all P > .05) among fAVR and mAVR patients, respectively. Likewise, mAVR patients also had less STS-predicted mortality (1.8 ± 0.98 vs 1.9 ± 0.95; P = .009) resulting in an O/E ratio of 0.722 vs 0.574. There was a clinical trend toward less median ICU stays (31 vs 51 hours; P = .075) for mAVR compared to fAVR patients, respectively. The hospital LOS was 1 day less in the mAVR patients (6 vs 7 days; P ≤ .001).
cohorts (Fig. 2). The Cox proportional hazard modeling identified CKD (hazard ratio [HR] 2.74, 95% confidence interval [CI]: 1.295.81), CHF (HR 1.84, 95% CI: 1.43-2.36), previous cardiac surgery (HR 1.53, 95% CI: 1.08-2.18), New York Heart Association class III/IV (HR 1.29, 95% CI: 1.00-1.68), and age (per year >65) (HR 1.04, 95% CI: 1.04-1.06) as contributors to decreased postoperative survival (Table 3). Variables that were noncontributory included operative (sternotomy) approach (P = .799), sex, CVA, cerebrovascular disease, peripheral vascular disease, emergent status, ejection fraction (%), hypertension, hypercholesterolemia, and diabetes. Discussion
Mid-term survival During the study period, 266 deaths were observed. Temporal differences in the number of procedures during the study period are highlighted in Fig. 1. mAVR patients had a greater unadjusted survival compared to fAVR patients, with mean survival times of 12.5 years and 11.9 years, respectively (P ≤ .025), but there was no difference in cumulative adjusted survival between the 2 patient
Establishing a benchmark operative approach for SAVR is extremely relevant in low-risk patients requiring an AVR, particularly in the current era of explosion in TAVR. We used our extensive, 15year, single-center experience to compare outcomes of fAVR and mAVR to help guide important clinical decisions. This large study has several noteworthy findings. We have demonstrated that mAVR and fAVR patients had similar operative mortality and in-hospital
Please cite this article as: S.A. Hirji et al., Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement? Surgery (2018), https://doi.org/10.1016/j.surg.2018.02.018
ARTICLE IN PRESS
JID: YMSY 4
[m5G;April 21, 2018;16:2]
S.A. Hirji et al. / Surgery 000 (2018) 1–6
Fig. 1. Temporal trends of fAVR and mAVR procedures in low-risk patients between 2002 and 2016.
Table 3 Cox proportional hazard modeling 95.0% CI Contributing factors
P≤
HR
Lower
Upper
CHF ≤2 weeks Age (per year >65) CKD Previous cardiac surgery NYHA class III/IV
.001 .001 .009 .016 .050
1.837 1.048 2.737 1.534 1.294
1.432 1.036 1.290 1.082 1.0 0 0
2.358 1.060 5.809 2.176 1.676
There were 266 deaths during observation period. Residual χ 2 = 7.352, P = .069. Noncontributory variables include sternotomy type (ie, mAVR versus fAVR), sex, cerebrovascular accident, peripheral vascular disease, emergent procedure, ejection fraction (%), hypertension, diabetes, and hypercholesterolemia. NYHA, New York Heart Association.
outcomes, such as stroke, reoperation rates for bleeding, and repeat valve procedures. Even after adjusting for various patientrelated factors, mAVR and fAVR patients had similar midterm survival; mAVR did, however, tend to result in a shorter hospital LOS and a shorter ICU stay. Given the high stakes against TAVR, this shorter LOS in the hospital and the ICU suggests that mAVR should stand as a benchmark against TAVR in low-risk patients. Given the changing landscape in patient profile and extent of comorbidities, there has been considerable interest and growth in TAVR. TAVR is a less invasive and less morbid approach to AVR that has been studied recently in comparison to medical therapy and to SAVR in patients with AS. The initial studies of TAVR enrolled inoperable and high-risk patients as defined by their STSPROM scores. In inoperable patients, TAVR compared to medical
therapy led to improved survival (69.3% vs 49.3%), a decreased rate of repeat hospitalization (22.3% vs 44.1%), and a decrease in cardiac symptoms (25.2% vs 58% at 1 year; all P < .05).11 In highrisk patients, TAVR compared to SAVR lead to a somewhat improved survival at 1 year (75.8% vs 73.2%; P = .44).2 More recently, the PARTNER 2 trial explored the feasibility and utility of TAVR in intermediate-risk patients and demonstrated similar rates of mortality (16.7% vs 18%), repeat hospitalization (19.6% vs 17.3%; P = .22) and stroke (6.2% vs 6.4%) compared to SAVR at 2 years (all P > .05).6 As a result, the US Food and Drug Administration (FDA) approved TAVR for intermediate-risk patients in addition to high-risk patients on the basis of these recent trials.12 Furthermore, current clinical practice guidelines of the American College of Cardiology/American Heart Association (ACC/AHA) and the European Society of Cardiology (ESC) recommend TAVR for treatment of severe AS in patients who are inoperable or at high risk for classic operative AVR.13,14 Recently, the ACC added TAVR as a grade IIa recommendation in AS patients with an intermediate operative risk.15 With the early success of existing efforts, the population eligible for TAVR has continued to expand, with clinicians now advocating for use of TAVR in low-risk patients. A recent randomized trial, the Nordic Aortic Valve Intervention Trial (NOTION), demonstrated that in low-surgical-risk patients with an average STS risk score of 3% TAVR achieved noninferiority compared to SAVR for the primary end-point of mortality or stroke at 1 year16 ; however, this study randomized only 18% of the screened patients, which likely limited its power. Currently, at least 2 major randomized controlled trials, the PARTNER 3 trial (NCT02675114) and The CoreValve Evolut R Low-Risk trial (NCT02701283), are randomizing low-risk patients to SAVR or TAVR. Although currently intermediate-risk
Please cite this article as: S.A. Hirji et al., Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement? Surgery (2018), https://doi.org/10.1016/j.surg.2018.02.018
JID: YMSY
ARTICLE IN PRESS
[m5G;April 21, 2018;16:2]
S.A. Hirji et al. / Surgery 000 (2018) 1–6
5
Fig. 2. Adjusted Cox proportional hazards survival curves for low-risk fAVR and mAVR patients.
patients include those with STS scores of 3 to 8, the PARTNER 2 trial classified intermediate patients with STS scores of 4 to 8. These 2 ongoing trials also have different cut-offs for low-risk. For example, the PARTNER 3 trial uses the <4% low-risk cut-off, while the CoreValve Evolut R Low-risk trial uses <3% as its study cut-off. For these reasons, we chose STS scores <4% as the cut-off, so that our results would be comparable to both these trials. While we await the results of these 2 trials (which will take time to complete), it is essential and very timely to understand contemporary outcomes of the conventional fAVR and the minimally invasive approach (mAVR). In recent years, minimally invasive aortic surgery has become established as an accepted approach to conventional sternotomy (fAVR) in the operative management of aortic disease, although this technique is limited to selected cardiac surgery centers, and in centers without TAVR availability. Compared to fAVR, mAVR is associated with improved clinical outcomes, especially in high-risk elderly patients. Our institution published our experience previously on 552 matched pairs comparing mAVR versus fAVR over a 10-year period, and found that mAVR patients had less ventilation times, shorter ICU stays, and shorter LOS, but no observed differences in short- or long-term survival or need for operative re-intervention.7 In a systematic review and meta-analysis of 26 studies and 4,546 patients undergoing AVR by Brown et al, mAVR was associated with shorter ICU and hospital LOS, less ventilation
times, and less blood loss within 24 hours, despite no difference in mortality.17 Similarly, Semsroth et al compared 118 matched pairs of mAVR and fAVR from 2005 to 2013 and found no significant differences in perioperative outcomes or 1-year survival, although a trend of better survival was observed with mAVR.18 These findings are consistent with our results. Importantly, several studies have also shown that mAVR results in improved patient satisfaction, decreased postoperative pain and narcotic use, improved cosmesis, faster recovery of respiratory function, and an earlier hospital discharge compared to fAVR.17 , 19-21 While TAVR is promising because it also seems to offer a clear advantage in terms of a decrease in acute kidney injury and need of blood transfusion, TAVR is associated with a greater risk of permanent pacemaker implantation (PPI), moderate-to-severe paravalvular regurgitation (PVL), and vascular complications.22 In addition, limited long-term data on durability of the TAVR valve raises concern. Daubert et al recently examined long-term performance of TAVR valves in terms of hemodynamic and valvular profile among patients who were enrolled previously in the PARTNER I trial and found no change in AV area or in total transvalvular or paravalvular aortic regurgitation over 5 years.23 Despite these results suggesting that valve performance and cardiac hemodynamics are stable after implantation of TAVR valves, valve durability is still unknown and has to be cautiously indicated in the young low-risk population.
Please cite this article as: S.A. Hirji et al., Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement? Surgery (2018), https://doi.org/10.1016/j.surg.2018.02.018
JID: YMSY 6
ARTICLE IN PRESS
[m5G;April 21, 2018;16:2]
S.A. Hirji et al. / Surgery 000 (2018) 1–6
Although this study had many merits, including our large sample size and robust clinical follow-up, it also has several limitations. First, our study was limited by its observational, singlecenter, nonrandomized nature. Moreover, there may be patient selection biases and other inherent confounders which could have affected the study results, although we attempted to adjust for several confounders. Second, the study lacked preoperative and postoperative echocardiographic data because many cases either were performed prior to the mandated STS reporting guidelines on data reporting or were referred from outside, nontertiary centers. Thus, accurate data assessment of hemodynamic performance of valves is limited. Third, common criteria outside of STS such as patient frailty and other comorbidities such as cirrhosis not captured by the STS score were not available. Fourth, our median follow-up was 5.3 years, which may have limited our ability to see any survival differences in a longer time period in this population. Despite its advantage, mAVR has not been used recently in part because of substantial physician turnover in our practice. We had several new faculty members who joined our institution and do not perform mAVR routinely, which explains the odd trend. Despite this, our results did not change by adding 2016 data. Using our extensive, 15-year, single-center experience, this study provides a robust benchmark for comparison of TAVR in lowrisk patients (STS score <4%). In these patients, mAVR results in shorter ICU and hospital LOS, while maintaining a similar rate of mortality, stroke, reoperation for bleeding, and mid-term survival compared to fAVR. With increasing patient preference for less invasive approaches and need for early recovery, mAVR should stand as a benchmark against TAVR in low-risk patients. References 1. Potter DD, Sundt 3rd TM, Zehr KJ, Dearani JA, Daly RC, Mullany CJ, et al. Operative risk of reoperative aortic valve replacement. J Thorac Cardiovasc Surg. 2005;129:94–103. 2. Smith CR, Leon MB, Mack MJ, Miller DC, Moses JW, Svensson LG, et al. Transcatheter versus surgical aortic-valve replacement in high-risk patients. N Engl J Med. 2011;364:2187–2198. 3. Leon MB, Smith CR, Mack M, Miller DC, Moses JW, Svensson LG, et al. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med. 2010;363:1597–1607. 4. Makkar RR, Fontana GP, Jilaihawi H, Kapadia S, Pichard AD, Douglas PS, et al. Transcatheter aortic-valve replacement for inoperable severe aortic stenosis. N Engl J Med. 2012;366:1696–1704. 5. Thourani VH, Kodali S, Makkar RR, Herrmann HC, Williams M, Babaliaros V, et al. Transcatheter aortic valve replacement versus surgical valve replacement in intermediate-risk patients: a propensity score analysis. Lancet. 2016;387:2218–2225. 6. Leon MB, Smith CR, Mack MJ, Makkar RR, Svensson LG, Kodali SK, et al. Transcatheter or Surgical Aortic-Valve Replacement in Intermediate-Risk Patients. N Engl J Med. 2016;374:1609–1620.
7. Neely RC, Boskovski MT, Gosev I, Kaneko T, McGurk S, Leacche M, et al. Minimally invasive aortic valve replacement versus aortic valve replacement through full sternotomy: the Brigham and Women’s Hospital experience. Ann Cardiothorac Surg. 2015;4:38–48. 8. Kaneko T, Loberman D, Gosev I, Rassam F, McGurk S, Leacche M, et al. Reoperative aortic valve replacement in the octogenarians-minimally invasive technique in the era of transcatheter valve replacement. J Thorac Cardiovasc Surg. 2014;147:155–162. 9. Gosev I, Neely RC, Leacche M, McGurk S, Kaneko T, Zeljko D, et al. The impact of a minimally invasive approach on reoperative aortic valve replacement. J Heart Valve Dis. 2015;24:181–186. 10. Gosev I, Kaneko T, McGurk S, McClure SR, Maloney A, Cohn LH. A 16-year experience in minimally invasive aortic valve replacement: context for the changing management of aortic valve disease. Innovations. 2014;9:104–110 discussion 110. 11. Leon MB, Smith CR, Mack M, Miller DC, Moses JW, Svensson LG, et al. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med. 2010;363:1597–1607. 12. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin 3rd JP, Guyton RA, et al. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;63:2438–2488. 13. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin 3rd JP, Guyton RA, et al. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;63:e57–185. 14. Vahanian A, Alfieri O, Andreotti F, Antunes MJ, Baron-Esquivias G, Baumgartner H, et al. [Guidelines on the management of valvular heart disease (version 2012). The Joint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS)]. G Ital Cardiol (Rome). 2013;14:167–214. 15. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin 3rd JP, Fleisher LA, et al. 2017 AHA/ACC Focused Update of the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. 2017. 16. Thyregod HG, Sondergaard L, Ihlemann N, Franzen O, Andersen LW, Hansen PB, et al. The Nordic aortic valve intervention (NOTION) trial comparing transcatheter versus surgical valve implantation: study protocol for a randomised controlled trial. Trials. 2013;14:11. 17. Brown ML, McKellar SH, Sundt TM, Schaff HV. Ministernotomy versus conventional sternotomy for aortic valve replacement: a systematic review and meta– analysis. J Thorac Cardiovasc Surg. 2009;137:670–679 e5. 18. Semsroth S, Matteucci Gothe R, Raith YR, de Brabandere K, Hanspeter E, Kilo J, et al. Comparison of Two Minimally Invasive Techniques and Median Sternotomy in Aortic Valve Replacement. Ann Thorac Surg. 2017;104:877–883. 19. Cohn LH. Minimally invasive aortic valve surgery: technical considerations and results with the parasternal approach. J Cardiac Surg. 1998;13:302–305. 20. Cohn LH, Adams DH, Couper GS, Bichell DP, Rosborough DM, Sears SP, et al. Minimally invasive cardiac valve surgery improves patient satisfaction while reducing costs of cardiac valve replacement and repair. Ann Surg. 1997;226:421–426 discussion 427-8. 21. Malaisrie SC, Barnhart GR, Farivar RS, Mehall J, Hummel B, Rodriguez E, et al. Current era minimally invasive aortic valve replacement: techniques and practice. J Thorac Cardiovasc Surg. 2014;147:6–14. 22. Elmaraezy A, Ismail A, Abushouk AI, Eltoomy M, Saad S, Negida A, et al. Efficacy and safety of transcatheter aortic valve replacement in aortic stenosis patients at low to moderate surgical risk: a comprehensive meta-analysis. BMC Cardiovasc Disord. 2017;17:234. 23. Daubert MA, Weissman NJ, Hahn RT, Pibarot P, Parvataneni R, Mack MJ, et al. Long-Term Valve Performance of TAVR and SAVR: A Report From the PARTNER I Trial. JACC Cardiovasc Imag. 2016.
Please cite this article as: S.A. Hirji et al., Minimally invasive versus full sternotomy aortic valve replacement in low-risk patients: Which will stand against transcatheter aortic valve replacement? Surgery (2018), https://doi.org/10.1016/j.surg.2018.02.018