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Effects of Pulmonary Thromboendarterectomy on Right-Sided Echocardiographic Parameters in Patients With Chronic Thromboembolic Pulmonary Hypertension
ORIGINAL ARTICLE EFFECTS OF PTE ON CTEPH
Effects of Pulmonary Thromboendarterectomy on Right-Sided Echocardiographic Parameters in Patients With Chronic Thromboembolic Pulmonary Hypertension GRACE CASACLANG-VERZOSA, MD; ROBERT B. MCCULLY, MD; JAE K. OH, MD; FLETCHER A. MILLER, JR, MD; AND CHRISTOPHER G. A. MCGREGOR, MB, FRCS OBJECTIVE: To determine the echocardiographic changes in the heart at 3 months and 1 year after pulmonary thromboendarterectomy (PTE) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). PATIENTS AND METHODS: Thirty-two adult patients who underwent PTE for CTEPH at the Mayo Clinic in Rochester, Minn, from 1997 to 2003 were included in the study. All underwent transthoracic echocardiography before surgery. Follow-up echocardiography was performed within 3 months of surgery in 28 patients and 1 year postoperatively in 17 patients. The results were compared with baseline data. RESULTS: Within 3 months after PTE, the right ventricular enddiastolic area decreased from 38.4±12.8 cm2 to 32.5±10.4 cm2 (mean difference, 5.8±10.4 cm2; P=.02). The right ventricular end-systolic area decreased from 30.4±12.1 cm2 to 24.1±8.6 cm2 (mean difference, 6.3±10.1 cm2; P=.008). The right ventricular systolic pressure decreased significantly from 92.6±22.0 mm Hg to 55.0±19.8 mm Hg (mean difference, 40.0±24.8 mm Hg; P<.001). Tricuspid regurgitation (TR) improved from a mean grade of 2.5±1.2 to 1.2±1.1 (mean difference, 1.5±1.0; P<.001). At 12 months, the right ventricular end-diastolic area, right ventricular end-systolic area, right ventricular systolic pressure, and TR also were significantly lower than baseline values. CONCLUSION: In patients with CTEPH who undergo PTE, echocardiographic measurements of right ventricular size, systolic pressure, and TR show significant improvement immediately after surgery, which is sustained for up to 1 year after surgery.
Mayo Clin Proc. 2006;81(6):777-782 CI = confidence interval; CTEPH = chronic thromboembolic pulmonary hypertension; IVC = inferior vena cava; LV = left ventricular; PAP = pulmonary artery pressure; PFO = patent foramen ovale; PTE = pulmonary thromboendarterectomy; RA = right atrial; RAP = RA pressure; RV = right ventricular; RVED = RV end-diastolic; RVES = RV end-systolic; RVSP = RV systolic pressure; TR = tricuspid regurgitation
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hronic thromboembolic pulmonary hypertension (CTEPH) is a progressive, debilitating disease caused by abnormally resolved thromboembolic material in the pulmonary vascular bed. Patients with CTEPH have a poor prognosis, with 5-year survival rates ranging from 10% to 30%.1 The clinical presentation of CTEPH includes a range of symptoms from shortness of breath to severe right-sided heart failure. The diagnosis is usually made after ventilation-perfusion radionuclide scanning and measurement of pulmonary hemodynamics. The severity of disease is then assessed by comprehensive echocardiographic examination, computed tomography, and pulmonary angiography. Mayo Clin Proc.
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Pulmonary thromboendarterectomy (PTE) is a successful treatment for pulmonary hypertension caused by chronic thromboembolic disease and, in specialized centers, has a reported mortality rate of 4.4%.2-4 Pulmonary thromboendarterectomy is indicated in symptomatic patients and in asymptomatic patients in whom pulmonary hypertension develops during exercise. Short-term and long-term outcome studies after PTE show significant and sustained improvement in pulmonary and right ventricular (RV) hemodynamics.1,5-11 Soon after PTE, mean pulmonary artery pressure (PAP), pulmonary vascular resistance,12,13 and RV volume overload decrease, and cardiac index improves.14,15 These hemodynamic changes are associated with improvement or resolution of tricuspid regurgitation (TR) in the perioperative period. Left ventricular (LV) enddiastolic volume and stroke volume also increase significantly. This hemodynamic improvement is accompanied by improvement in New York Heart Association classification immediately after surgery.5 Transthoracic 2-dimensional Doppler echocardiography is an accepted and readily available noninvasive imaging method to monitor right heart function and PAPs. Depending on the severity and duration of the disease, echocardiography shows variable degrees of right atrial (RA) and RV enlargement, abnormal RV systolic function, TR, D-shaped LV cavity, decreased LV size, and abnormal LV systolic and diastolic functions.16-19 Agitated saline contrast echocardiography may be used to demonstrate a patent foramen ovale (PFO).2,3 Although the hemodynamic effects of PTE have been reported, few detailed descriptions of echocardiographic changes after PTE have been published. The current study assessed changes in right-sided echocardiographic parameters in patients with CTEPH who underwent PTE.
From the Division of Cardiovascular Diseases (G.C.-V., R.B.M., J.K.O., F.A.M.) and Division of Cardiovascular Surgery (C.G.A.M.), Mayo Clinic College of Medicine, Rochester, Minn. Individual reprints of this article are not available. Address correspondence to Jae K. Oh, MD, Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, 200 First St SW, Rochester, MN 55905 (e-mail: [email protected]). © 2006 Mayo Foundation for Medical Education and Research
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FIGURE 1. Transthoracic apical 4-chamber echocardiographic view used for the area-length method of measuring right ventricular (RV, outlined) volume. Line through the RV indicates length. The line is drawn from the level of the tricuspid annulus plane to the tip of the RV apex. LA = left atrium; LV = left ventricle; RA = right atrium.
PATIENTS AND METHODS The clinical records of all 44 patients who underwent PTE for CTEPH at one surgical service (C.G.A.M.) at the Mayo Clinic in Rochester, Minn, from 1997 to 2003 were reviewed retrospectively. Patients without both baseline and follow-up echocardiograms for comparison (12 patients) were excluded. Thirty-two patients met the inclusion criteria. Repeated echocardiography was performed within 3 months of PTE for 28 patients, and follow-up echocardiography was performed after 1 year in 17 patients. The study was approved by the Mayo Foundation Institutional Review Board.
and respiratory motion of the inferior vena cava (IVC) as seen in the subcostal view. If the IVC diameter was less than 2.5 cm and decreased by 50%, the RAP was estimated to be approximately 5 mm Hg. If the IVC diameter decreased by less than 50%, the RAP was estimated to be approximately 10 mm Hg. An IVC diameter of greater than 2.5 cm that collapsed by less than 50% was assigned an RAP of 15 mm Hg. Any size larger than 2.5 cm that did not change with respiration was assigned an RAP of 20 mm Hg. The severity of TR was assessed by color flow Doppler imaging as follows: grade 0, trivial or no TR; grade 1, mild; grade 2, moderate; grade 3, moderate to severe; grade 4, severe. Mild TR is characterized by flow disturbance in systole localized to the area adjacent to the valve closure plane. Moderate TR fills between 5 and 10 cm2 of the RA; moderate to severe TR fills more than 10 cm2 of the RA. Tricuspid regurgitation is severe when it is associated with systolic reversal of the hepatic vein.20,21 Change in RV area, on the basis of RVED and RVES areas, was calculated as follows: change in RV area = [(RVED area − RVES area)/RVED area] × 100%. Right ventricular myocardial performance index22 was calculated as follows: RV myocardial performance index = (isovolumic contraction time + isovolumic relaxation time)/RV outflow ejection time. STATISTICAL ANALYSES Preoperative and postoperative echocardiographic values are expressed as mean ± SD. Baseline and postoperative data were compared by using a 2-tailed Wilcoxon signed rank test. P<.05 was considered significant. RESULTS
ECHOCARDIOGRAPHY Patients underwent transthoracic echocardiography before and after surgery. Right ventricular end-diastolic (RVED) and RV end-systolic (RVES) areas were measured by the area-length method using a transthoracic apical 4-chamber view (Figure 1). The RVED volume was calculated with the following equation: volume = (0.85 × [A2/L]), where A = area (cm2) of the ventricle from the apical 2- or 4chamber view, and L = long-axis length (cm) of the ventricle from the view shown in Figure 1. The largest area during diastole and the smallest area during systole were measured off-line by a single observer (G.C.-V.). Three consecutive measurements were made for each cardiac cycle and were averaged for each patient. Right ventricular systolic pressure (RVSP) was determined using the peak TR jet velocity and estimated RA pressure (RVSP = 4[TR velocity]2 + estimated RA pressure). Right atrial pressure (RAP) was estimated by the size 778
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The 32 study patients were 15 men and 17 women. The mean ± SD age was 55.4±13.5 years (range, 21-77 years). All patients presented with right-sided heart failure. Eleven patients had a history of thrombophlebitis or deep venous thrombosis, 3 had antiphospholipid syndrome, 2 had coexisting malignancy, and 10 had no definite underlying cause of CTEPH. For the other 6 patients, 1 each had essential thrombocytopenia, essential thrombocytosis, previous cerebral-to-atrial shunt, decreased protein S activity, KlippelTrénaunay-Weber syndrome, and an undetermined hypercoagulability disease. During PTE, 9 patients underwent closure of PFO, 1 had atrial septal defect closure, 3 had concomitant coronary artery bypass grafting, 2 had tricuspid valve annuloplasty, and 1 had both PFO closure and tricuspid valve annuloplasty. The 12 patients (8 men) who were excluded from the study had a mean ± SD age of 54.6±9 years and a mean
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EFFECTS OF PTE ON CTEPH
FIGURE 2. Left, Echocardiographic short-axis view showing a D-shaped left ventricle (LV) during diastole. Right, M-mode of the same view as in left. The interventricular septum (IVS) shows flattened and paradoxical motion. RV = right ventricle.
preoperative systolic PAP of 81.9±16 mm Hg. Eight had a history of deep venous thrombosis, and the rest had indeterminate causes of CTEPH. BASELINE ECHOCARDIOGRAPHY All 32 patients underwent routine transthoracic echocardiography at a mean of 28±22 days before scheduled surgery. The mean RVSP was 91.8±20.5 mm Hg. Tricuspid regurgitation was grade 0 in 1, grade 1 in 7, grade 2 in 10, grade 3 in 6, and grade 4 in 8 patients (mean, 2.4±1.2). The RV function was decreased in 29 of 32 patients. The RV index of myocardial performance was measurable in 27 patients (mean, 0.66±0.24). The mean RVED area was 42.0±12.3 cm2, and the RVES area was 34.0±12.0 cm2. The RA was dilated in all patients. A D-shaped LV cavity was observed in 19 patients (Figure 2). The mean LV ejection fraction was 63.0%±6.4%. A shunt at the atrial septum was detected in 9 patients. Pulmonary pressures obtained by cardiac catheterization were available in all patients. The mean systolic PAP was 81±14.5 mm Hg, mean diastolic PAP was 31±10 mm Hg, and mean PAP was 49±10 mm Hg. The RVSP by echocardiography correlated well with systolic PAP obtained by cardiac catheterization (r=.51, P=.003; Figure 3). FOLLOW-UP ECHOCARDIOGRAPHY Of the 32 patients, 28 underwent repeated echocardiography within 3 months after PTE (median, 9 days; range, 1-86 days), and 17 had follow-up echocardiography within approximately 1 year after surgery (mean, 350±76 days; median, 365 days; range, 212-511 days). Within 3 months after PTE, the RVED area and RVES area decreased substantially (RVED area mean decrease, 5.8±10.4 cm2; P=.02; RVES area mean decrease, 6.3±10.1 cm2; P=.008) (Table 1). The RVSP decreased significantly (mean deMayo Clin Proc.
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crease, 40.0±24.8 mm Hg; P<.001). The severity of TR improved from grade 2.5 to 1.2 (P<.001; Figure 4). For the patients with follow-up echocardiography performed at 12 months, the RVED area and RVES area were lower than baseline (RVED area mean decrease, 10.5±14.0 cm2, P=.02; RVES area mean decrease, 11.0±12.0 cm2, P=.006) (Table 2). The RVSP was also significantly lower than baseline (mean decrease, 35.2±34.2 mm Hg; P=.001). The severity of TR improved, with a mean decrease of 0.9±1.2 (median, 1.0; P=.008) at 12 months (Table 2). We further analyzed change in RVSP, RV size, and TR severity by excluding those who underwent tricuspid valve repair (25 patients remained). We found consistent and statistically significant improvement at 3 months in RVSP (mean difference, 40.0±25.4; 95% confidence interval [CI], 28.0-51.0; P<.001), RVED area (mean difference, 6.1±11.2; 95% CI, 0.6-12.0; P=.04), RVES area (mean
FIGURE 3. Correlation of right ventricular systolic pressure (RVSP) obtained by echocardiography with systolic pulmonary artery pressure (SPAP) obtained by cardiac catheterization.
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TABLE 1. Comparison of Echocardiographic Findings Before and 3 Months After Pulmonary Thromboendarterectomy (n=28)* Value Parameter
Baseline
3 Mo
Mean difference
95% CI
TR velocity (m/s) RVSP (mm Hg) TR severity (grade) RVED area (cm2) RVES area (cm2) RV area change (%) Cardiac output (L/m)
4.4±0.6 92.6±22.0 2.5±1.2 38.4±12.8 30.4±12.1 21.0±8.6 5.4±1.8
3.3±0.6 55.0±19.8 1.2±1.1 32.5±10.4 24.1±8.6 28.0±7.5 5.6±1.7
1.2±0.7 40.0±24.8 1.5±1.0 5.8±10.4 6.3±10.1 –7.8±14.0 –0.6±1.6
0.9 to –1.5 30.0 to –50.0 1.1 to –1.9 1.1 to –10.6 1.7 to –11.0 –11.5 to 1.9 –2.0 to 0.7
P value† <.001 <.001 <.001 .02 .008 .19 .30
*Values are mean ± SD. CI = confidence interval; RV = right ventricular; RVED = RV end-diastolic; RVES = RV end-systolic; RVSP = RV systolic pressure; TR = tricuspid regurgitation. †Wilcoxon signed rank test.
difference, 7.6±10.4; 95% CI, 2.4-13.0; P=.005), and TR severity (mean difference, 1.4±1.0; 95% CI, 0.9-1.8; P<.001). Significant improvement was also seen at 12 months in RVSP (mean difference, 31.0±34.4; 95% CI, 1250; P<.004), RVED area (mean difference, 10.4±15.3; 95% CI, 0.12-21.0; P=.05), RVES area (mean difference, 11.7±13.2; 95% CI, 3.0-21.0; P=.02), and TR severity (mean difference, 0.8±1.2; 95% CI, 0.13-1.5; P=.02). We investigated whether a further decrease in TR velocity, RVSP, and RV size occurred over time by comparing echocardiographic results at 3 months and 12 months. For the 13 patients who had echocardiographic studies at both 3
FIGURE 4. Change in grade of tricuspid regurgitation (TR) for each patient before and 3 months after pulmonary thromboendarterectomy (PTE). Each line connects the points representing TR grade for one patient before and after PTE.
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months and 12 months after surgery, we found no significant change in the parameters at these 2 time points (Table 3). Mean TR severity was similarly mild (grade 1) at 3 and 12 months. The RV myocardial performance index improved from 0.64 to 0.44 at 3 months and from 0.67 to 0.56 at 12 months, but this improvement was not statistically significant (P=.40). DISCUSSION Chronic thromboembolic pulmonary hypertension occurs as a result of incomplete anatomic and hemodynamic recovery from an acute thromboembolic event. A clot in a branch pulmonary vessel can propagate in situ, which results in complete obstruction.23 Secondary endothelial changes, manifested as hyperplasia of arterioles distal to the site of obstruction, can develop, which further increases pulmonary vascular resistance.24,25 Increased vascular tone and fixed vascular obstruction contribute to the total pulmonary resistance.26 For some patients in whom complete resolution occurs spontaneously or after treatment, recurrent embolism can eventually lead to pulmonary hypertension. Pengo et al,27 studying symptomatic CTEPH after pulmonary embolism, reported incidences of 1.0% at 5 months, 3.1% at 1 year, and 3.8% at 2 years. Patients with CTEPH usually present with dyspnea on exertion, decreased exercise tolerance, syncope, and evidence of rightsided heart failure, such as hepatosplenomegaly, lower extremity edema, and ascites. Chronic pulmonary hypertension from thrombotic disease has a poor prognosis, which is proportional to the severity of pulmonary hypertension. Patients with a mean PAP greater than 30 mm Hg had a 30% survival rate, and those with a mean PAP greater than 50 mm Hg had a 10% survival rate at 5 years.1 The high PAP associated with CTEPH exerts pressure overload on the RV, which results in functional and morphological alterations in the RV. The RV becomes hyper-
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EFFECTS OF PTE ON CTEPH
TABLE 2. Comparison of Echocardiographic Findings Before and 12 Months After Pulmonary Thromboendarterectomy (n=17)* Value Parameter
Baseline
12 Mo
Mean difference
95% CI
P value†
TR velocity (m/s) RVSP (mm Hg) TR severity (grade) RVED area (cm2) RVES area (cm2) RV area change (%) Cardiac output (L/m)
4.3±0.5 90.0±15.5 2.4±1.0 37.8±12.9 30.0±12.4 21.6±10.8 4.9±2.0
3.2±0.9 54.8±31.0 1.5±1.2 28.5±8.2 20.0±6.4 30.2±9.8 5.4±1.2
1.1±1.0 35.2±34.2 0.9±1.2 10.5±14.0 11.0±12.0 −9.1±13.0 −0.5±1.7
0.6 to 1.6 17.6 to 53.0 0.3 to 1.5 2.0 to 19.0 3.6 to 18.0 −17.0 to −1.1 −1.5 to 0.43
.001 .001 .008 .02 .006 .03 .10
*Values are mean ± SD. CI = confidence interval; RV = right ventricular; RVED = RV end-diastolic; RVES = RV end-systolic; RVSP = RV systolic pressure; TR = tricuspid regurgitation. †Wilcoxon signed rank test.
trophied, and the right-sided chambers enlarge. The papillary muscles are displaced apically and laterally, and the tricuspid annulus dilates. Tricuspid regurgitation develops and becomes more severe as RV function worsens. The increased workload demand on the RV eventually leads to heart failure. Occasionally, a PFO with right-to-left shunting is evident. The PFO serves as a mechanism to equalize pressures between the right and left atria.28 Although the disease is chronic, pathologic specimens from CTEPH hearts did not show fibrosis consistently.17 This may in part explain the reversibility of RV dysfunction after a successful thromboendarterectomy. The resectability of the chronic thromboembolic material, influenced by extent and location of disease, determines postoperative outcome.29 The disease is bilateral in each patient but is more severe on the right than the left side.30 Marked elevation of PAP, severity of TR, and RV failure are not contraindications to PTE. We observed patients with a baseline RVSP greater than 100 mm Hg who did as well as those with a lower pressure. The severity of TR improved immediately after PTE in all but 2 patients (Figure 4), both of whom had distal thromboembolism that
was surgically inaccessible. Tricuspid valve repair was performed in only 3 patients. Improvement in RV function was consistent across the spectrum of preoperative values. Currently, Doppler echocardiography is used to evaluate patients before PTE. Intraoperatively, echocardiography can assist the surgeon in evaluating the presence and severity of TR. Echocardiography can be used to identify the presence of a PFO or other coexisting heart disease that may need surgical correction, and it can be used for postsurgical assessment. Hemodynamic improvement seen after endarterectomy can be measured immediately in the operating room. After surgical intervention, Doppler echocardiography can reliably provide information on cardiopulmonary hemodynamics and morphology of the heart. Echocardiography enables the clinician to identify patients with persistent postoperative pulmonary hypertension and RV dysfunction and identify the patients who may need further therapy. However, to date, no Doppler echocardiographic parameter can predict perioperative outcome. Long-term continuous improvement in cardiac hemodynamics after PTE is not well documented. In the current study, no
TABLE 3. Comparison of Echocardiographic Findings for Patients Evaluated at 3 Months and 12 Months After Pulmonary Thromboendarterectomy (n=13)* Value Parameter
3 Mo
12 Mo
Mean difference
95% CI
P value†
TR velocity (m/s) RVSP (mm Hg) TR severity (grade) RVED area (cm2) RVES area (cm2) RV area change (%) Cardiac output (L/m)
3.3±0.7 59.0±24.0 1.1±1.3 31.8±5.3 23.6±2.8 25.1±8.4 5.2±1.6
3.4±1.0 60.0±34.0 1.6±1.4 29.4±8.7 20.9±7.0 29.0±10.0 5.7±1.2
0.05±0.7 −1.3±24.0 0.5±1.2 2.0±8.2 2.4±6.2 4.4±13.4 −0.8±1.8
−0.4 to 0.5 –16.0 to 13.0 –1.1 to 0.6 –3.6 to 8.0 –1.7 to 7.0 –14.0 to 4.5 –2.4 to 0.8
.60 .90 .20 .40 .20 .40 .30
*Values are mean ± SD. CI = confidence interval; RV = right ventricular; RVED = RV end-diastolic; RVES = RV end-systolic; RVSP = RV systolic pressure; TR = tricuspid regurgitation. †Wilcoxon signed rank test.
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significant difference was observed between RVSP, RV size, and TR severity at 3 months and 12 months. These data suggest that the benefit of PTE to CTEPH is immediate and sustained. However, further long-term follow-up of patients after PTE is necessary to establish the long-term benefits of surgery. Echocardiography is preferred for long-term follow-up of these patients because of its simplicity, low cost, and availability compared with other techniques, such as computed tomography, magnetic resonance imaging, or pulmonary angiography. Whereas computed tomography and magnetic resonance imaging can show the presence or absence of a clot, 2-dimensional and Doppler echocardiography can evaluate RV volume and function and pulmonary pressures. CONCLUSION In patients with CTEPH who undergo PTE, echocardiographic measurements of RV size, systolic pressure, and TR show significant improvements immediately after surgery that are sustained for up to 1 year after surgery. Generally, TR improves without tricuspid valve repair. Long-term follow-up of these patients is recommended to understand the long-term effects of PTE and to identify Doppler echocardiographic predictors of survival.
REFERENCES 1. Riedel M, Stanek V, Widimsky J, Prerovsky I. Long term follow-up of patients with pulmonary thromboembolism: late prognosis and evolution of hemodynamic and respiratory data. Chest. 1982;81:151-158. 2. Jamieson SW, Auger WR, Fedullo PF, et al. Experience and results with 150 pulmonary thromboendarterectomy operations over a 29-month period. J Thorac Cardiovasc Surg. 1993;106:116-126. 3. Jamieson SW. Pulmonary thromboendarterectomy [editorial]. Heart. 1998;79:118-120. 4. Jamieson SW, Nomura K. Indications for and the results of pulmonary thromboendarterectomy for thromboembolic pulmonary hypertension. Semin Vasc Surg. 2000;13:236-244. 5. D’Armini AM, Cattadori B, Monterosso C, et al. Pulmonary thromboendarterectomy in patients with chronic thromboembolic pulmonary hypertension: hemodynamic characteristics and changes. Eur J Cardiothorac Surg. 2000; 18:696-701. 6. Daily PO, Dembitzsky WP, Iversen S, Moser KM, Auger W. Current early results of pulmonary thromboendarterectomy for chronic pulmonary embolism. Eur J Cardiothorac Surg. 1990;4:117-121. 7. Kramm T, Mayer E, Dahm M, et al. Long-term results after thromboendarterectomy for chronic pulmonary embolism. Eur J Cardiothorac Surg. 1999; 15:579-583. 8. Mayer E, Dahm M, Hake U, et al. Mid-term results of pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension. Ann Thorac Surg. 1996;61:1788-1792. 9. Ribeiro A, Lindmarker P, Johnsson H, Juhlin-Dannfelt A, Jorfeldt L. Pulmonary embolism: a follow-up study of the relation between the degree of
782
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right ventricle overload and the extent of perfusion defects. J Intern Med. 1999; 245:601-610. 10. Ribeiro A, Lindmarker P, Johnsson H, Juhlin-Dannfelt A, Jorfeldt L. Pulmonary embolism: one-year follow-up with echocardiography Doppler and five-year survival analysis. Circulation. 1999;99:1325-1330. 11. Ritchie M, Waggoner AD, Davila-Roman VG, Barzilai B, Trulock EP, Eisenberg PR. Echocardiographic characterization of the improvement in right ventricular function in patients with severe pulmonary hypertension after single-lung transplantation. J Am Coll Cardiol. 1993;22:1170-1174. 12. Dittrich HC, Nicod PH, Chow LC, Chappuis FP, Moser KM, Peterson KL. Early changes of right heart geometry after pulmonary thromboendarterectomy. J Am Coll Cardiol. 1988;11:937-943. 13. Dittrich HC, Chow LC, Nicod PH. Early improvement in left ventricular diastolic function after relief of chronic right ventricular pressure overload. Circulation. 1989;80:823-830. 14. Dunning J, McNeil K. Pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension. Thorax. 1999;54:755-756. 15. McGregor C, Almeida A, Dunn WF, Edwards BS, McGoon MD, Breen JF. Improvement in right ventricular function and size and pulmonary hemodynamics following pulmonary thromboendarterectomy. Chest. 2002;122 (suppl):22S. 16. Auger WR, Channick RN, Kerr KM, Fedullo PF. Evaluation of patients with suspected chronic thromboembolic pulmonary hypertension. Semin Thorac Cardiovasc Surg. 1999;11:179-190. 17. Bradley SP, Auger WR, Moser KM, Fedullo PF, Channick RN, Bloor CM. Right ventricular pathology in chronic pulmonary hypertension. Am J Cardiol. 1996;78:584-587. 18. Dittrich HC, McCann HA, Blanchard DG. Cardiac structure and function in chronic thromboembolic pulmonary hypertension. Am J Card Imaging. 1994;8:18-27. 19. Fedullo PF, Auger WR, Channick RN, Moser KM, Jamieson SW. Chronic thromboembolic pulmonary hypertension. Clin Chest Med. 1995;16: 353-374. 20. Shapira Y, Porter A, Wurzel M, Vaturi M, Sagie A. Evaluation of tricuspid regurgitation severity: echocardiographic and clinical correlation. J Am Soc Echocardiogr. 1998;11:652-659. 21. Gonzalez-Vilchez F, Zarauza J, Vazquez de Prada JA, et al. Assessment of tricuspid regurgitation by Doppler color flow imaging: angiographic correlation. Int J Cardiol. 1994;44:275-283. 22. Tei C, Dujardin KS, Hodge DO, et al. Doppler echocardiographic index for assessment of global right ventricular function. J Am Soc Echocardiogr. 1996;9:838-847. 23. Auger WR, Permpikul P, Moser KM. Lupus anticoagulant, heparin use, and thrombocytopenia in patients with chronic thromboembolic pulmonary hypertension: a preliminary report. Am J Med. 1995;99:392-396. 24. Auger WR, Fedullo PF, Moser KM, Buchbinder M, Peterson KL. Chronic major-vessel thromboembolic pulmonary artery obstruction: appearance at angiography. Radiology. 1992;182:393-398. 25. Moser KM, Auger WR, Fedullo PF. Chronic major-vessel thromboembolic pulmonary hypertension. Circulation. 1990;81:1735-1743. 26. Dantzker DR, Bower JS. Partial reversibility of chronic pulmonary hypertension caused by pulmonary thromboembolic disease. Am Rev Respir Dis. 1981;124:129-131. 27. Pengo V, Lensing AW, Prins MH, et al. Incidence of chronic thromboembolic pulmonary hypertension after pulmonary embolism. N Engl J Med. 2004;350:2257-2264. 28. Jamieson SW, Kapelanski DP, Sakakibara N, et al. Pulmonary endarterectomy: experience and lessons learned in 1,500 cases. Ann Thorac Surg. 2003; 76:1457-1462. 29. Thistlethwaite PA, Mo M, Madani MM, et al. Operative classification of thromboembolic disease determines outcome after pulmonary endarterectomy. J Thorac Cardiovasc Surg. 2002;124:1203-1211. 30. Blauwet LA, Edwards WD, Tazelaar HD, McGregor CG. Surgical pathology of pulmonary thromboendarterectomy: a study of 54 cases from 1990 to 2001. Hum Pathol. 2003;34:1290-1298.
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Effects of Pulmonary Thromboendarterectomy on Right-Sided Echocardiographic Parameters in Patients With Chronic Thromboembolic Pulmonary Hypertension GRACE CASACLANG-VERZOSA, MD; ROBERT B. MCCULLY, MD; JAE K. OH, MD; FLETCHER A. MILLER, JR, MD; AND CHRISTOPHER G. A. MCGREGOR, MB, FRCS OBJECTIVE: To determine the echocardiographic changes in the heart at 3 months and 1 year after pulmonary thromboendarterectomy (PTE) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). PATIENTS AND METHODS: Thirty-two adult patients who underwent PTE for CTEPH at the Mayo Clinic in Rochester, Minn, from 1997 to 2003 were included in the study. All underwent transthoracic echocardiography before surgery. Follow-up echocardiography was performed within 3 months of surgery in 28 patients and 1 year postoperatively in 17 patients. The results were compared with baseline data. RESULTS: Within 3 months after PTE, the right ventricular enddiastolic area decreased from 38.4±12.8 cm2 to 32.5±10.4 cm2 (mean difference, 5.8±10.4 cm2; P=.02). The right ventricular end-systolic area decreased from 30.4±12.1 cm2 to 24.1±8.6 cm2 (mean difference, 6.3±10.1 cm2; P=.008). The right ventricular systolic pressure decreased significantly from 92.6±22.0 mm Hg to 55.0±19.8 mm Hg (mean difference, 40.0±24.8 mm Hg; P<.001). Tricuspid regurgitation (TR) improved from a mean grade of 2.5±1.2 to 1.2±1.1 (mean difference, 1.5±1.0; P<.001). At 12 months, the right ventricular end-diastolic area, right ventricular end-systolic area, right ventricular systolic pressure, and TR also were significantly lower than baseline values. CONCLUSION: In patients with CTEPH who undergo PTE, echocardiographic measurements of right ventricular size, systolic pressure, and TR show significant improvement immediately after surgery, which is sustained for up to 1 year after surgery.
Mayo Clin Proc. 2006;81(6):777-782 CI = confidence interval; CTEPH = chronic thromboembolic pulmonary hypertension; IVC = inferior vena cava; LV = left ventricular; PAP = pulmonary artery pressure; PFO = patent foramen ovale; PTE = pulmonary thromboendarterectomy; RA = right atrial; RAP = RA pressure; RV = right ventricular; RVED = RV end-diastolic; RVES = RV end-systolic; RVSP = RV systolic pressure; TR = tricuspid regurgitation
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hronic thromboembolic pulmonary hypertension (CTEPH) is a progressive, debilitating disease caused by abnormally resolved thromboembolic material in the pulmonary vascular bed. Patients with CTEPH have a poor prognosis, with 5-year survival rates ranging from 10% to 30%.1 The clinical presentation of CTEPH includes a range of symptoms from shortness of breath to severe right-sided heart failure. The diagnosis is usually made after ventilation-perfusion radionuclide scanning and measurement of pulmonary hemodynamics. The severity of disease is then assessed by comprehensive echocardiographic examination, computed tomography, and pulmonary angiography. Mayo Clin Proc.
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Pulmonary thromboendarterectomy (PTE) is a successful treatment for pulmonary hypertension caused by chronic thromboembolic disease and, in specialized centers, has a reported mortality rate of 4.4%.2-4 Pulmonary thromboendarterectomy is indicated in symptomatic patients and in asymptomatic patients in whom pulmonary hypertension develops during exercise. Short-term and long-term outcome studies after PTE show significant and sustained improvement in pulmonary and right ventricular (RV) hemodynamics.1,5-11 Soon after PTE, mean pulmonary artery pressure (PAP), pulmonary vascular resistance,12,13 and RV volume overload decrease, and cardiac index improves.14,15 These hemodynamic changes are associated with improvement or resolution of tricuspid regurgitation (TR) in the perioperative period. Left ventricular (LV) enddiastolic volume and stroke volume also increase significantly. This hemodynamic improvement is accompanied by improvement in New York Heart Association classification immediately after surgery.5 Transthoracic 2-dimensional Doppler echocardiography is an accepted and readily available noninvasive imaging method to monitor right heart function and PAPs. Depending on the severity and duration of the disease, echocardiography shows variable degrees of right atrial (RA) and RV enlargement, abnormal RV systolic function, TR, D-shaped LV cavity, decreased LV size, and abnormal LV systolic and diastolic functions.16-19 Agitated saline contrast echocardiography may be used to demonstrate a patent foramen ovale (PFO).2,3 Although the hemodynamic effects of PTE have been reported, few detailed descriptions of echocardiographic changes after PTE have been published. The current study assessed changes in right-sided echocardiographic parameters in patients with CTEPH who underwent PTE.
From the Division of Cardiovascular Diseases (G.C.-V., R.B.M., J.K.O., F.A.M.) and Division of Cardiovascular Surgery (C.G.A.M.), Mayo Clinic College of Medicine, Rochester, Minn. Individual reprints of this article are not available. Address correspondence to Jae K. Oh, MD, Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, 200 First St SW, Rochester, MN 55905 (e-mail: [email protected]). © 2006 Mayo Foundation for Medical Education and Research
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FIGURE 1. Transthoracic apical 4-chamber echocardiographic view used for the area-length method of measuring right ventricular (RV, outlined) volume. Line through the RV indicates length. The line is drawn from the level of the tricuspid annulus plane to the tip of the RV apex. LA = left atrium; LV = left ventricle; RA = right atrium.
PATIENTS AND METHODS The clinical records of all 44 patients who underwent PTE for CTEPH at one surgical service (C.G.A.M.) at the Mayo Clinic in Rochester, Minn, from 1997 to 2003 were reviewed retrospectively. Patients without both baseline and follow-up echocardiograms for comparison (12 patients) were excluded. Thirty-two patients met the inclusion criteria. Repeated echocardiography was performed within 3 months of PTE for 28 patients, and follow-up echocardiography was performed after 1 year in 17 patients. The study was approved by the Mayo Foundation Institutional Review Board.
and respiratory motion of the inferior vena cava (IVC) as seen in the subcostal view. If the IVC diameter was less than 2.5 cm and decreased by 50%, the RAP was estimated to be approximately 5 mm Hg. If the IVC diameter decreased by less than 50%, the RAP was estimated to be approximately 10 mm Hg. An IVC diameter of greater than 2.5 cm that collapsed by less than 50% was assigned an RAP of 15 mm Hg. Any size larger than 2.5 cm that did not change with respiration was assigned an RAP of 20 mm Hg. The severity of TR was assessed by color flow Doppler imaging as follows: grade 0, trivial or no TR; grade 1, mild; grade 2, moderate; grade 3, moderate to severe; grade 4, severe. Mild TR is characterized by flow disturbance in systole localized to the area adjacent to the valve closure plane. Moderate TR fills between 5 and 10 cm2 of the RA; moderate to severe TR fills more than 10 cm2 of the RA. Tricuspid regurgitation is severe when it is associated with systolic reversal of the hepatic vein.20,21 Change in RV area, on the basis of RVED and RVES areas, was calculated as follows: change in RV area = [(RVED area − RVES area)/RVED area] × 100%. Right ventricular myocardial performance index22 was calculated as follows: RV myocardial performance index = (isovolumic contraction time + isovolumic relaxation time)/RV outflow ejection time. STATISTICAL ANALYSES Preoperative and postoperative echocardiographic values are expressed as mean ± SD. Baseline and postoperative data were compared by using a 2-tailed Wilcoxon signed rank test. P<.05 was considered significant. RESULTS
ECHOCARDIOGRAPHY Patients underwent transthoracic echocardiography before and after surgery. Right ventricular end-diastolic (RVED) and RV end-systolic (RVES) areas were measured by the area-length method using a transthoracic apical 4-chamber view (Figure 1). The RVED volume was calculated with the following equation: volume = (0.85 × [A2/L]), where A = area (cm2) of the ventricle from the apical 2- or 4chamber view, and L = long-axis length (cm) of the ventricle from the view shown in Figure 1. The largest area during diastole and the smallest area during systole were measured off-line by a single observer (G.C.-V.). Three consecutive measurements were made for each cardiac cycle and were averaged for each patient. Right ventricular systolic pressure (RVSP) was determined using the peak TR jet velocity and estimated RA pressure (RVSP = 4[TR velocity]2 + estimated RA pressure). Right atrial pressure (RAP) was estimated by the size 778
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The 32 study patients were 15 men and 17 women. The mean ± SD age was 55.4±13.5 years (range, 21-77 years). All patients presented with right-sided heart failure. Eleven patients had a history of thrombophlebitis or deep venous thrombosis, 3 had antiphospholipid syndrome, 2 had coexisting malignancy, and 10 had no definite underlying cause of CTEPH. For the other 6 patients, 1 each had essential thrombocytopenia, essential thrombocytosis, previous cerebral-to-atrial shunt, decreased protein S activity, KlippelTrénaunay-Weber syndrome, and an undetermined hypercoagulability disease. During PTE, 9 patients underwent closure of PFO, 1 had atrial septal defect closure, 3 had concomitant coronary artery bypass grafting, 2 had tricuspid valve annuloplasty, and 1 had both PFO closure and tricuspid valve annuloplasty. The 12 patients (8 men) who were excluded from the study had a mean ± SD age of 54.6±9 years and a mean
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EFFECTS OF PTE ON CTEPH
FIGURE 2. Left, Echocardiographic short-axis view showing a D-shaped left ventricle (LV) during diastole. Right, M-mode of the same view as in left. The interventricular septum (IVS) shows flattened and paradoxical motion. RV = right ventricle.
preoperative systolic PAP of 81.9±16 mm Hg. Eight had a history of deep venous thrombosis, and the rest had indeterminate causes of CTEPH. BASELINE ECHOCARDIOGRAPHY All 32 patients underwent routine transthoracic echocardiography at a mean of 28±22 days before scheduled surgery. The mean RVSP was 91.8±20.5 mm Hg. Tricuspid regurgitation was grade 0 in 1, grade 1 in 7, grade 2 in 10, grade 3 in 6, and grade 4 in 8 patients (mean, 2.4±1.2). The RV function was decreased in 29 of 32 patients. The RV index of myocardial performance was measurable in 27 patients (mean, 0.66±0.24). The mean RVED area was 42.0±12.3 cm2, and the RVES area was 34.0±12.0 cm2. The RA was dilated in all patients. A D-shaped LV cavity was observed in 19 patients (Figure 2). The mean LV ejection fraction was 63.0%±6.4%. A shunt at the atrial septum was detected in 9 patients. Pulmonary pressures obtained by cardiac catheterization were available in all patients. The mean systolic PAP was 81±14.5 mm Hg, mean diastolic PAP was 31±10 mm Hg, and mean PAP was 49±10 mm Hg. The RVSP by echocardiography correlated well with systolic PAP obtained by cardiac catheterization (r=.51, P=.003; Figure 3). FOLLOW-UP ECHOCARDIOGRAPHY Of the 32 patients, 28 underwent repeated echocardiography within 3 months after PTE (median, 9 days; range, 1-86 days), and 17 had follow-up echocardiography within approximately 1 year after surgery (mean, 350±76 days; median, 365 days; range, 212-511 days). Within 3 months after PTE, the RVED area and RVES area decreased substantially (RVED area mean decrease, 5.8±10.4 cm2; P=.02; RVES area mean decrease, 6.3±10.1 cm2; P=.008) (Table 1). The RVSP decreased significantly (mean deMayo Clin Proc.
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crease, 40.0±24.8 mm Hg; P<.001). The severity of TR improved from grade 2.5 to 1.2 (P<.001; Figure 4). For the patients with follow-up echocardiography performed at 12 months, the RVED area and RVES area were lower than baseline (RVED area mean decrease, 10.5±14.0 cm2, P=.02; RVES area mean decrease, 11.0±12.0 cm2, P=.006) (Table 2). The RVSP was also significantly lower than baseline (mean decrease, 35.2±34.2 mm Hg; P=.001). The severity of TR improved, with a mean decrease of 0.9±1.2 (median, 1.0; P=.008) at 12 months (Table 2). We further analyzed change in RVSP, RV size, and TR severity by excluding those who underwent tricuspid valve repair (25 patients remained). We found consistent and statistically significant improvement at 3 months in RVSP (mean difference, 40.0±25.4; 95% confidence interval [CI], 28.0-51.0; P<.001), RVED area (mean difference, 6.1±11.2; 95% CI, 0.6-12.0; P=.04), RVES area (mean
FIGURE 3. Correlation of right ventricular systolic pressure (RVSP) obtained by echocardiography with systolic pulmonary artery pressure (SPAP) obtained by cardiac catheterization.
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TABLE 1. Comparison of Echocardiographic Findings Before and 3 Months After Pulmonary Thromboendarterectomy (n=28)* Value Parameter
Baseline
3 Mo
Mean difference
95% CI
TR velocity (m/s) RVSP (mm Hg) TR severity (grade) RVED area (cm2) RVES area (cm2) RV area change (%) Cardiac output (L/m)
4.4±0.6 92.6±22.0 2.5±1.2 38.4±12.8 30.4±12.1 21.0±8.6 5.4±1.8
3.3±0.6 55.0±19.8 1.2±1.1 32.5±10.4 24.1±8.6 28.0±7.5 5.6±1.7
1.2±0.7 40.0±24.8 1.5±1.0 5.8±10.4 6.3±10.1 –7.8±14.0 –0.6±1.6
0.9 to –1.5 30.0 to –50.0 1.1 to –1.9 1.1 to –10.6 1.7 to –11.0 –11.5 to 1.9 –2.0 to 0.7
P value† <.001 <.001 <.001 .02 .008 .19 .30
*Values are mean ± SD. CI = confidence interval; RV = right ventricular; RVED = RV end-diastolic; RVES = RV end-systolic; RVSP = RV systolic pressure; TR = tricuspid regurgitation. †Wilcoxon signed rank test.
difference, 7.6±10.4; 95% CI, 2.4-13.0; P=.005), and TR severity (mean difference, 1.4±1.0; 95% CI, 0.9-1.8; P<.001). Significant improvement was also seen at 12 months in RVSP (mean difference, 31.0±34.4; 95% CI, 1250; P<.004), RVED area (mean difference, 10.4±15.3; 95% CI, 0.12-21.0; P=.05), RVES area (mean difference, 11.7±13.2; 95% CI, 3.0-21.0; P=.02), and TR severity (mean difference, 0.8±1.2; 95% CI, 0.13-1.5; P=.02). We investigated whether a further decrease in TR velocity, RVSP, and RV size occurred over time by comparing echocardiographic results at 3 months and 12 months. For the 13 patients who had echocardiographic studies at both 3
FIGURE 4. Change in grade of tricuspid regurgitation (TR) for each patient before and 3 months after pulmonary thromboendarterectomy (PTE). Each line connects the points representing TR grade for one patient before and after PTE.
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months and 12 months after surgery, we found no significant change in the parameters at these 2 time points (Table 3). Mean TR severity was similarly mild (grade 1) at 3 and 12 months. The RV myocardial performance index improved from 0.64 to 0.44 at 3 months and from 0.67 to 0.56 at 12 months, but this improvement was not statistically significant (P=.40). DISCUSSION Chronic thromboembolic pulmonary hypertension occurs as a result of incomplete anatomic and hemodynamic recovery from an acute thromboembolic event. A clot in a branch pulmonary vessel can propagate in situ, which results in complete obstruction.23 Secondary endothelial changes, manifested as hyperplasia of arterioles distal to the site of obstruction, can develop, which further increases pulmonary vascular resistance.24,25 Increased vascular tone and fixed vascular obstruction contribute to the total pulmonary resistance.26 For some patients in whom complete resolution occurs spontaneously or after treatment, recurrent embolism can eventually lead to pulmonary hypertension. Pengo et al,27 studying symptomatic CTEPH after pulmonary embolism, reported incidences of 1.0% at 5 months, 3.1% at 1 year, and 3.8% at 2 years. Patients with CTEPH usually present with dyspnea on exertion, decreased exercise tolerance, syncope, and evidence of rightsided heart failure, such as hepatosplenomegaly, lower extremity edema, and ascites. Chronic pulmonary hypertension from thrombotic disease has a poor prognosis, which is proportional to the severity of pulmonary hypertension. Patients with a mean PAP greater than 30 mm Hg had a 30% survival rate, and those with a mean PAP greater than 50 mm Hg had a 10% survival rate at 5 years.1 The high PAP associated with CTEPH exerts pressure overload on the RV, which results in functional and morphological alterations in the RV. The RV becomes hyper-
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EFFECTS OF PTE ON CTEPH
TABLE 2. Comparison of Echocardiographic Findings Before and 12 Months After Pulmonary Thromboendarterectomy (n=17)* Value Parameter
Baseline
12 Mo
Mean difference
95% CI
P value†
TR velocity (m/s) RVSP (mm Hg) TR severity (grade) RVED area (cm2) RVES area (cm2) RV area change (%) Cardiac output (L/m)
4.3±0.5 90.0±15.5 2.4±1.0 37.8±12.9 30.0±12.4 21.6±10.8 4.9±2.0
3.2±0.9 54.8±31.0 1.5±1.2 28.5±8.2 20.0±6.4 30.2±9.8 5.4±1.2
1.1±1.0 35.2±34.2 0.9±1.2 10.5±14.0 11.0±12.0 −9.1±13.0 −0.5±1.7
0.6 to 1.6 17.6 to 53.0 0.3 to 1.5 2.0 to 19.0 3.6 to 18.0 −17.0 to −1.1 −1.5 to 0.43
.001 .001 .008 .02 .006 .03 .10
*Values are mean ± SD. CI = confidence interval; RV = right ventricular; RVED = RV end-diastolic; RVES = RV end-systolic; RVSP = RV systolic pressure; TR = tricuspid regurgitation. †Wilcoxon signed rank test.
trophied, and the right-sided chambers enlarge. The papillary muscles are displaced apically and laterally, and the tricuspid annulus dilates. Tricuspid regurgitation develops and becomes more severe as RV function worsens. The increased workload demand on the RV eventually leads to heart failure. Occasionally, a PFO with right-to-left shunting is evident. The PFO serves as a mechanism to equalize pressures between the right and left atria.28 Although the disease is chronic, pathologic specimens from CTEPH hearts did not show fibrosis consistently.17 This may in part explain the reversibility of RV dysfunction after a successful thromboendarterectomy. The resectability of the chronic thromboembolic material, influenced by extent and location of disease, determines postoperative outcome.29 The disease is bilateral in each patient but is more severe on the right than the left side.30 Marked elevation of PAP, severity of TR, and RV failure are not contraindications to PTE. We observed patients with a baseline RVSP greater than 100 mm Hg who did as well as those with a lower pressure. The severity of TR improved immediately after PTE in all but 2 patients (Figure 4), both of whom had distal thromboembolism that
was surgically inaccessible. Tricuspid valve repair was performed in only 3 patients. Improvement in RV function was consistent across the spectrum of preoperative values. Currently, Doppler echocardiography is used to evaluate patients before PTE. Intraoperatively, echocardiography can assist the surgeon in evaluating the presence and severity of TR. Echocardiography can be used to identify the presence of a PFO or other coexisting heart disease that may need surgical correction, and it can be used for postsurgical assessment. Hemodynamic improvement seen after endarterectomy can be measured immediately in the operating room. After surgical intervention, Doppler echocardiography can reliably provide information on cardiopulmonary hemodynamics and morphology of the heart. Echocardiography enables the clinician to identify patients with persistent postoperative pulmonary hypertension and RV dysfunction and identify the patients who may need further therapy. However, to date, no Doppler echocardiographic parameter can predict perioperative outcome. Long-term continuous improvement in cardiac hemodynamics after PTE is not well documented. In the current study, no
TABLE 3. Comparison of Echocardiographic Findings for Patients Evaluated at 3 Months and 12 Months After Pulmonary Thromboendarterectomy (n=13)* Value Parameter
3 Mo
12 Mo
Mean difference
95% CI
P value†
TR velocity (m/s) RVSP (mm Hg) TR severity (grade) RVED area (cm2) RVES area (cm2) RV area change (%) Cardiac output (L/m)
3.3±0.7 59.0±24.0 1.1±1.3 31.8±5.3 23.6±2.8 25.1±8.4 5.2±1.6
3.4±1.0 60.0±34.0 1.6±1.4 29.4±8.7 20.9±7.0 29.0±10.0 5.7±1.2
0.05±0.7 −1.3±24.0 0.5±1.2 2.0±8.2 2.4±6.2 4.4±13.4 −0.8±1.8
−0.4 to 0.5 –16.0 to 13.0 –1.1 to 0.6 –3.6 to 8.0 –1.7 to 7.0 –14.0 to 4.5 –2.4 to 0.8
.60 .90 .20 .40 .20 .40 .30
*Values are mean ± SD. CI = confidence interval; RV = right ventricular; RVED = RV end-diastolic; RVES = RV end-systolic; RVSP = RV systolic pressure; TR = tricuspid regurgitation. †Wilcoxon signed rank test.
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significant difference was observed between RVSP, RV size, and TR severity at 3 months and 12 months. These data suggest that the benefit of PTE to CTEPH is immediate and sustained. However, further long-term follow-up of patients after PTE is necessary to establish the long-term benefits of surgery. Echocardiography is preferred for long-term follow-up of these patients because of its simplicity, low cost, and availability compared with other techniques, such as computed tomography, magnetic resonance imaging, or pulmonary angiography. Whereas computed tomography and magnetic resonance imaging can show the presence or absence of a clot, 2-dimensional and Doppler echocardiography can evaluate RV volume and function and pulmonary pressures. CONCLUSION In patients with CTEPH who undergo PTE, echocardiographic measurements of RV size, systolic pressure, and TR show significant improvements immediately after surgery that are sustained for up to 1 year after surgery. Generally, TR improves without tricuspid valve repair. Long-term follow-up of these patients is recommended to understand the long-term effects of PTE and to identify Doppler echocardiographic predictors of survival.
REFERENCES 1. Riedel M, Stanek V, Widimsky J, Prerovsky I. Long term follow-up of patients with pulmonary thromboembolism: late prognosis and evolution of hemodynamic and respiratory data. Chest. 1982;81:151-158. 2. Jamieson SW, Auger WR, Fedullo PF, et al. Experience and results with 150 pulmonary thromboendarterectomy operations over a 29-month period. J Thorac Cardiovasc Surg. 1993;106:116-126. 3. Jamieson SW. Pulmonary thromboendarterectomy [editorial]. Heart. 1998;79:118-120. 4. Jamieson SW, Nomura K. Indications for and the results of pulmonary thromboendarterectomy for thromboembolic pulmonary hypertension. Semin Vasc Surg. 2000;13:236-244. 5. D’Armini AM, Cattadori B, Monterosso C, et al. Pulmonary thromboendarterectomy in patients with chronic thromboembolic pulmonary hypertension: hemodynamic characteristics and changes. Eur J Cardiothorac Surg. 2000; 18:696-701. 6. Daily PO, Dembitzsky WP, Iversen S, Moser KM, Auger W. Current early results of pulmonary thromboendarterectomy for chronic pulmonary embolism. Eur J Cardiothorac Surg. 1990;4:117-121. 7. Kramm T, Mayer E, Dahm M, et al. Long-term results after thromboendarterectomy for chronic pulmonary embolism. Eur J Cardiothorac Surg. 1999; 15:579-583. 8. Mayer E, Dahm M, Hake U, et al. Mid-term results of pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension. Ann Thorac Surg. 1996;61:1788-1792. 9. Ribeiro A, Lindmarker P, Johnsson H, Juhlin-Dannfelt A, Jorfeldt L. Pulmonary embolism: a follow-up study of the relation between the degree of
782
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right ventricle overload and the extent of perfusion defects. J Intern Med. 1999; 245:601-610. 10. Ribeiro A, Lindmarker P, Johnsson H, Juhlin-Dannfelt A, Jorfeldt L. Pulmonary embolism: one-year follow-up with echocardiography Doppler and five-year survival analysis. Circulation. 1999;99:1325-1330. 11. Ritchie M, Waggoner AD, Davila-Roman VG, Barzilai B, Trulock EP, Eisenberg PR. Echocardiographic characterization of the improvement in right ventricular function in patients with severe pulmonary hypertension after single-lung transplantation. J Am Coll Cardiol. 1993;22:1170-1174. 12. Dittrich HC, Nicod PH, Chow LC, Chappuis FP, Moser KM, Peterson KL. Early changes of right heart geometry after pulmonary thromboendarterectomy. J Am Coll Cardiol. 1988;11:937-943. 13. Dittrich HC, Chow LC, Nicod PH. Early improvement in left ventricular diastolic function after relief of chronic right ventricular pressure overload. Circulation. 1989;80:823-830. 14. Dunning J, McNeil K. Pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension. Thorax. 1999;54:755-756. 15. McGregor C, Almeida A, Dunn WF, Edwards BS, McGoon MD, Breen JF. Improvement in right ventricular function and size and pulmonary hemodynamics following pulmonary thromboendarterectomy. Chest. 2002;122 (suppl):22S. 16. Auger WR, Channick RN, Kerr KM, Fedullo PF. Evaluation of patients with suspected chronic thromboembolic pulmonary hypertension. Semin Thorac Cardiovasc Surg. 1999;11:179-190. 17. Bradley SP, Auger WR, Moser KM, Fedullo PF, Channick RN, Bloor CM. Right ventricular pathology in chronic pulmonary hypertension. Am J Cardiol. 1996;78:584-587. 18. Dittrich HC, McCann HA, Blanchard DG. Cardiac structure and function in chronic thromboembolic pulmonary hypertension. Am J Card Imaging. 1994;8:18-27. 19. Fedullo PF, Auger WR, Channick RN, Moser KM, Jamieson SW. Chronic thromboembolic pulmonary hypertension. Clin Chest Med. 1995;16: 353-374. 20. Shapira Y, Porter A, Wurzel M, Vaturi M, Sagie A. Evaluation of tricuspid regurgitation severity: echocardiographic and clinical correlation. J Am Soc Echocardiogr. 1998;11:652-659. 21. Gonzalez-Vilchez F, Zarauza J, Vazquez de Prada JA, et al. Assessment of tricuspid regurgitation by Doppler color flow imaging: angiographic correlation. Int J Cardiol. 1994;44:275-283. 22. Tei C, Dujardin KS, Hodge DO, et al. Doppler echocardiographic index for assessment of global right ventricular function. J Am Soc Echocardiogr. 1996;9:838-847. 23. Auger WR, Permpikul P, Moser KM. Lupus anticoagulant, heparin use, and thrombocytopenia in patients with chronic thromboembolic pulmonary hypertension: a preliminary report. Am J Med. 1995;99:392-396. 24. Auger WR, Fedullo PF, Moser KM, Buchbinder M, Peterson KL. Chronic major-vessel thromboembolic pulmonary artery obstruction: appearance at angiography. Radiology. 1992;182:393-398. 25. Moser KM, Auger WR, Fedullo PF. Chronic major-vessel thromboembolic pulmonary hypertension. Circulation. 1990;81:1735-1743. 26. Dantzker DR, Bower JS. Partial reversibility of chronic pulmonary hypertension caused by pulmonary thromboembolic disease. Am Rev Respir Dis. 1981;124:129-131. 27. Pengo V, Lensing AW, Prins MH, et al. Incidence of chronic thromboembolic pulmonary hypertension after pulmonary embolism. N Engl J Med. 2004;350:2257-2264. 28. Jamieson SW, Kapelanski DP, Sakakibara N, et al. Pulmonary endarterectomy: experience and lessons learned in 1,500 cases. Ann Thorac Surg. 2003; 76:1457-1462. 29. Thistlethwaite PA, Mo M, Madani MM, et al. Operative classification of thromboembolic disease determines outcome after pulmonary endarterectomy. J Thorac Cardiovasc Surg. 2002;124:1203-1211. 30. Blauwet LA, Edwards WD, Tazelaar HD, McGregor CG. Surgical pathology of pulmonary thromboendarterectomy: a study of 54 cases from 1990 to 2001. Hum Pathol. 2003;34:1290-1298.
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