- Email: [email protected]
Hospital-Level Factors Associated With Mortality After Endovascular and Open Abdominal Aortic Aneurysm Repair
1128 Abstracts
patients with heterozygous familial hypercholesterolaemia do not reach recommended LDL-C concentrations (Pijlman AH et al, Atherosclerosis 2010;209:189-94). Recent work suggests a new class of monoclonal antibodies against PCSK9 can result in highly significant decreases in LDL-C concentrations and that these drugs have an overall favorable safety profile. The authors aimed to investigate the safety and efficacy of anacetrapib, a cholesteryl ester transfer protein inhibitor, in patients with heterozygous familial hypercholesterolaemia. This was a multicenter, randomized, double blind, placebo controlled, phase III study. It included patients aged 18 to 80 years with a genotype-confirmed, or clinical diagnosis of, heterozygous familial hypercholesterolemia who were on optimum lipid lowering treatment for at least 6 weeks with an LDL-C concentration of $2.59 mmol/L without cardiovascular disease or $1.81 mmol/L with cardiovascular disease. Patients were drawn from 26 lipid clinics in nine countries. They were randomly allocated 2:1 to oral anacetrapib 100 mg, or placebo, for 52 weeks with a 12 week post-treatment follow-up. Patients, care providers, and those assessing outcomes were blinded throughout the study. The primary outcome was percent change from baseline LDL-C concentration. Analysis was with a constrained longitudinal repeated measures model. Between February 10, 2012 and February 12, 2014, 204 patients were allocated to anacetrapib and 102 to placebo. One patient in the anacetrapib group did not receive the drug. At week 52, anacetrapib reduced mean LDL-C concentration from 3.3 mmol/L (standard deviation, 0.8) to 2.1 mmol/L (0.8; % change 36% [95% CI, 39.5 to 32.5%]) compared with an increase with placebo from 3.4 mmol/L (1.2) to 3.5 mmol/L [1.6; % change 3.7% (1.2 to 8.6%]), with a difference in percent change between anacetrapib and placebo of 39.7% (95% CI, 45.7 to 33.7; P < .0001). Cardiovascular events were increased in patients given anacetrapib compared with those given placebo (4 [2%] of 203 vs 0 [0%] of 102; P ¼ .15444), with the proportion of adverse events leading to discontinuation similar in the two groups (12 [6%] of 203 vs 5 [5%] of 102). Comment: The data continue to accumulate that targeting the apolipoprotein B receptor is a promising approach to the control of cholesterol levels in patients difficult to control with traditional statin therapy. While relative LDL-C reduction achieved with PCSK9 inhibition is more pronounced than that with anacetrapib, differences in terms of hard cardiovascular endpoints still remain to be established. Potential reductions of LDL-C in patients with familial hypercholesterolaemia beyond that achieved with statin medications are now possible. Hopefully, this will eventually reduce major cardiovascular events in patients with still recalcitrant LDL cholesterol levels when treated with standard statin medications. Prophylactic Inferior Vena Cava Filter Placement Does Not Result in a Survival Benefit for Trauma Patients Hemmila MR, Osborne NH, Henke PK, et al. Ann Surg 2015; 262:577-85. Conclusion: High rates of prophylactic inferior vena cava (IVC) filter placement have no effect on reducing trauma patient mortality and are associated with an increase in deep venous thrombosis (DVT). Summary: Prophylactic placement of an IVC filter is controversial. Bariatric surgery patients, spine surgery patients and head injury patients have been considered individuals at high risk for venous thromboembolism (VTE) and complications of pharmacologic VTE prophylaxis and therefore are potential candidates for prophylactic IVC filter placement. Analysis of the Nationwide In-patient Database suggests the incidence of prophylactic IVC filter placement has been increasing at a higher rate than filter placement after a VTE event (157% vs 42% adjusted rate increases from 19982005; Moore PS et al, J Vasc Surg 2010;52:118-26). The authors utilized the data from the Michigan Trauma Quality Improvement Program (MTQIP), a statewide collaborative quality initiative sponsored by health insurers and focused on trauma. They examined the relationship between prophylactic IVC filter placement and mortality in higher risk cohorts of trauma patients. They also investigated potential association of prophylactic IVC filter placement with the development of subsequent VTE events. Trauma quality collaborative data from 2010-2014 were analyzed. Patients were excluded who had no signs of life or who had injury severity scores of <9,
JOURNAL OF VASCULAR SURGERY April 2016
hospitalization <3 days, or received an IVC filter after a VTE event. Risk adjusted rates for prophylactic IVC filter placement were calculated and hospitals placed into a quartiles of IVC filter use. Mortality rates by quartile were compared. The association of deep vein thrombosis (DVT) with the presence of an IVC filter, accounting for type and timing of initiation and pharmacologic VTE prophylaxis, was also determined. A prophylactic IVC filter was placed in 803 (2%) of 39,456 patients. There was significant hospital variability (0.6%-9.6%) in rates of IVC filter utilization. Rates of prophylactic IVC filter placement within quartiles were 0.7%, 1.3%, 2.1%, 4.6%, respectively. IVC filter use by quartile showed no variation in mortality. Adjusting for pharmacologic VTE prophylaxis and patient factors, prophylactic IVC filter placement was associated with an increased incidence of DVT (OR, 1.83; 95% CI, 1.15-2.93; P ¼ .01). Comment: Clearly there appears to be an epidemic of IVC filter use for inappropriate indications. There are, however, patients who do die of venous thromboembolism and who may have benefited from placement of an IVC filter. The question is not whether there are too many prophylactic IVC filters placed. The answer is almost for sure yes. A better focus for future investigation would be to identify who are the truly high risk patients who receive more benefit than harm from placement of an IVC filter. We should not “throw the baby out with the bathwater”. Hospital-Level Factors Associated With Mortality After Endovascular and Open Abdominal Aortic Aneurysm Repair Hicks CW, Wick EC, Canner JK, et al. JAMA Surgery 2015;150:632-6. Conclusion: Outcomes for both open abdominal aortic aneurysm (AAA) repair and endovascular AAA repair are greatly dependent on hospital-level effects. Summary: Hospital volume is known to be a variable that influences mortality in vascular surgery. Mortality in open AAA repair is lower in high volume hospitals than lower volume institutions (Beck AW et al, J Vasc Surg 2009;49:838-44, and van Beek SC et al, J Vasc Surg 2013;58:1452-7). The Leap Frog Group has suggested minimum volume criteria of 50 open AAA repairs per year as part of evidence-based hospital safety standards. There is less information available on relationship between hospital volume and endovascular AAA repair. The authors therefore decided to perform an analysis of hospital effects on mortality following open aneurysm repair (OAR) and endovascular aneurysm repair (EVAR). This was a retrospective analysis of the American College of Surgeons NSQIP database and was conducted on all patients undergoing OAR or EVAR from July 1, 2010 to November 30, 2012. Patients were identified with CPT codes. Primary outcome measures were adjusted 30day observed to expected mortality ratios and were compared based on hospital type (academic vs community) and hospital size (100-299 beds vs 300-500 beds vs >500 beds). Data on 11,250 patients (2466 OARs and 8784 EVARs) were analyzed. EVAR was performed more frequently than OAR at both academic (78.8%) and community (68.2%) hospitals. Overall 30-day mortality was 14% for OAR and 4.3% for EVAR (P < .0001). Hospital size was significantly associated with mortality for OAR (observed to expected mortality ratio (OEMR): >500 beds, 0.88 vs 300-500 beds, 1.11 vs 100-299 beds, 1.59; P ¼ .01), but not EVAR (P ¼ .27). In contrast, hospital type was significantly associated with mortality for EVAR [OEMR: academic 0.60, vs community 2.60; (P < .001) but not OAR (P ¼ .46)]. Multivariable analysis of hospital level factors suggested that for all outcomes academic hospital type was the single most significant predictor of reduced mortality following AAA repair (OEMR: academic, 0.91 vs community, 2.00; P ¼ .05). Comment: The authors considered this “ a preliminary report” as such it is probably a bit simplistic to state that you’re clearly better off having your AAA repaired in a large academic medical center than in a community hospital. Nevertheless, the data does suggest that regionalized centers of excellent for the care of the AAA patient should be considered. Such centers potentially allow a critical mass of persons of excellence, hospital resources and standardized treatment protocols, all of which may contribute to improved care of the patients with AAAs.
patients with heterozygous familial hypercholesterolaemia do not reach recommended LDL-C concentrations (Pijlman AH et al, Atherosclerosis 2010;209:189-94). Recent work suggests a new class of monoclonal antibodies against PCSK9 can result in highly significant decreases in LDL-C concentrations and that these drugs have an overall favorable safety profile. The authors aimed to investigate the safety and efficacy of anacetrapib, a cholesteryl ester transfer protein inhibitor, in patients with heterozygous familial hypercholesterolaemia. This was a multicenter, randomized, double blind, placebo controlled, phase III study. It included patients aged 18 to 80 years with a genotype-confirmed, or clinical diagnosis of, heterozygous familial hypercholesterolemia who were on optimum lipid lowering treatment for at least 6 weeks with an LDL-C concentration of $2.59 mmol/L without cardiovascular disease or $1.81 mmol/L with cardiovascular disease. Patients were drawn from 26 lipid clinics in nine countries. They were randomly allocated 2:1 to oral anacetrapib 100 mg, or placebo, for 52 weeks with a 12 week post-treatment follow-up. Patients, care providers, and those assessing outcomes were blinded throughout the study. The primary outcome was percent change from baseline LDL-C concentration. Analysis was with a constrained longitudinal repeated measures model. Between February 10, 2012 and February 12, 2014, 204 patients were allocated to anacetrapib and 102 to placebo. One patient in the anacetrapib group did not receive the drug. At week 52, anacetrapib reduced mean LDL-C concentration from 3.3 mmol/L (standard deviation, 0.8) to 2.1 mmol/L (0.8; % change 36% [95% CI, 39.5 to 32.5%]) compared with an increase with placebo from 3.4 mmol/L (1.2) to 3.5 mmol/L [1.6; % change 3.7% (1.2 to 8.6%]), with a difference in percent change between anacetrapib and placebo of 39.7% (95% CI, 45.7 to 33.7; P < .0001). Cardiovascular events were increased in patients given anacetrapib compared with those given placebo (4 [2%] of 203 vs 0 [0%] of 102; P ¼ .15444), with the proportion of adverse events leading to discontinuation similar in the two groups (12 [6%] of 203 vs 5 [5%] of 102). Comment: The data continue to accumulate that targeting the apolipoprotein B receptor is a promising approach to the control of cholesterol levels in patients difficult to control with traditional statin therapy. While relative LDL-C reduction achieved with PCSK9 inhibition is more pronounced than that with anacetrapib, differences in terms of hard cardiovascular endpoints still remain to be established. Potential reductions of LDL-C in patients with familial hypercholesterolaemia beyond that achieved with statin medications are now possible. Hopefully, this will eventually reduce major cardiovascular events in patients with still recalcitrant LDL cholesterol levels when treated with standard statin medications. Prophylactic Inferior Vena Cava Filter Placement Does Not Result in a Survival Benefit for Trauma Patients Hemmila MR, Osborne NH, Henke PK, et al. Ann Surg 2015; 262:577-85. Conclusion: High rates of prophylactic inferior vena cava (IVC) filter placement have no effect on reducing trauma patient mortality and are associated with an increase in deep venous thrombosis (DVT). Summary: Prophylactic placement of an IVC filter is controversial. Bariatric surgery patients, spine surgery patients and head injury patients have been considered individuals at high risk for venous thromboembolism (VTE) and complications of pharmacologic VTE prophylaxis and therefore are potential candidates for prophylactic IVC filter placement. Analysis of the Nationwide In-patient Database suggests the incidence of prophylactic IVC filter placement has been increasing at a higher rate than filter placement after a VTE event (157% vs 42% adjusted rate increases from 19982005; Moore PS et al, J Vasc Surg 2010;52:118-26). The authors utilized the data from the Michigan Trauma Quality Improvement Program (MTQIP), a statewide collaborative quality initiative sponsored by health insurers and focused on trauma. They examined the relationship between prophylactic IVC filter placement and mortality in higher risk cohorts of trauma patients. They also investigated potential association of prophylactic IVC filter placement with the development of subsequent VTE events. Trauma quality collaborative data from 2010-2014 were analyzed. Patients were excluded who had no signs of life or who had injury severity scores of <9,
JOURNAL OF VASCULAR SURGERY April 2016
hospitalization <3 days, or received an IVC filter after a VTE event. Risk adjusted rates for prophylactic IVC filter placement were calculated and hospitals placed into a quartiles of IVC filter use. Mortality rates by quartile were compared. The association of deep vein thrombosis (DVT) with the presence of an IVC filter, accounting for type and timing of initiation and pharmacologic VTE prophylaxis, was also determined. A prophylactic IVC filter was placed in 803 (2%) of 39,456 patients. There was significant hospital variability (0.6%-9.6%) in rates of IVC filter utilization. Rates of prophylactic IVC filter placement within quartiles were 0.7%, 1.3%, 2.1%, 4.6%, respectively. IVC filter use by quartile showed no variation in mortality. Adjusting for pharmacologic VTE prophylaxis and patient factors, prophylactic IVC filter placement was associated with an increased incidence of DVT (OR, 1.83; 95% CI, 1.15-2.93; P ¼ .01). Comment: Clearly there appears to be an epidemic of IVC filter use for inappropriate indications. There are, however, patients who do die of venous thromboembolism and who may have benefited from placement of an IVC filter. The question is not whether there are too many prophylactic IVC filters placed. The answer is almost for sure yes. A better focus for future investigation would be to identify who are the truly high risk patients who receive more benefit than harm from placement of an IVC filter. We should not “throw the baby out with the bathwater”. Hospital-Level Factors Associated With Mortality After Endovascular and Open Abdominal Aortic Aneurysm Repair Hicks CW, Wick EC, Canner JK, et al. JAMA Surgery 2015;150:632-6. Conclusion: Outcomes for both open abdominal aortic aneurysm (AAA) repair and endovascular AAA repair are greatly dependent on hospital-level effects. Summary: Hospital volume is known to be a variable that influences mortality in vascular surgery. Mortality in open AAA repair is lower in high volume hospitals than lower volume institutions (Beck AW et al, J Vasc Surg 2009;49:838-44, and van Beek SC et al, J Vasc Surg 2013;58:1452-7). The Leap Frog Group has suggested minimum volume criteria of 50 open AAA repairs per year as part of evidence-based hospital safety standards. There is less information available on relationship between hospital volume and endovascular AAA repair. The authors therefore decided to perform an analysis of hospital effects on mortality following open aneurysm repair (OAR) and endovascular aneurysm repair (EVAR). This was a retrospective analysis of the American College of Surgeons NSQIP database and was conducted on all patients undergoing OAR or EVAR from July 1, 2010 to November 30, 2012. Patients were identified with CPT codes. Primary outcome measures were adjusted 30day observed to expected mortality ratios and were compared based on hospital type (academic vs community) and hospital size (100-299 beds vs 300-500 beds vs >500 beds). Data on 11,250 patients (2466 OARs and 8784 EVARs) were analyzed. EVAR was performed more frequently than OAR at both academic (78.8%) and community (68.2%) hospitals. Overall 30-day mortality was 14% for OAR and 4.3% for EVAR (P < .0001). Hospital size was significantly associated with mortality for OAR (observed to expected mortality ratio (OEMR): >500 beds, 0.88 vs 300-500 beds, 1.11 vs 100-299 beds, 1.59; P ¼ .01), but not EVAR (P ¼ .27). In contrast, hospital type was significantly associated with mortality for EVAR [OEMR: academic 0.60, vs community 2.60; (P < .001) but not OAR (P ¼ .46)]. Multivariable analysis of hospital level factors suggested that for all outcomes academic hospital type was the single most significant predictor of reduced mortality following AAA repair (OEMR: academic, 0.91 vs community, 2.00; P ¼ .05). Comment: The authors considered this “ a preliminary report” as such it is probably a bit simplistic to state that you’re clearly better off having your AAA repaired in a large academic medical center than in a community hospital. Nevertheless, the data does suggest that regionalized centers of excellent for the care of the AAA patient should be considered. Such centers potentially allow a critical mass of persons of excellence, hospital resources and standardized treatment protocols, all of which may contribute to improved care of the patients with AAAs.