Biomedical subjects
Publications and source records attributed to Mark J Eisenberg.
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BACKGROUND: Through the AMI-QUEBEC Study we sought to describe delays to reperfusion therapy for ST-segment elevation myocardial infarction (STEMI) and to identify factors associated with prolonged delays. METHODS: We reviewed the charts of all consecutive patients with STEMI admitted to 17 hospitals in the province of Quebec in 2003 to obtain data on the time from presentation to reperfusion therapy. Data were available for 1189 (83.0%) of 1432 patients. RESULTS: The median delay to reperfusion therapy was 32 minutes (first and third quartile [Q1, Q3] 20, 49) for 535 patients who received fibrinolytic therapy, 109 minutes (Q1, Q3 79, 150) for 455 patients who underwent primary percutaneous coronary intervention (PCI) at the initial hospital of presentation and 142 minutes (Q1, Q3 115, 194) for 199 patients who underwent primary PCI after an interhospital transfer. Patients who presented outside daytime working hours, those who received primary PCI and those who required interhospital transfer for primary PCI were less likely to receive reperfusion therapy within current recommended times (odds ratios [ORs] 0.49, 0.56 and 0.15, respectively). Increased age was associated with prolonged delays only among patients who received fibrinolytic therapy (OR for each 10-year increase in age 0.95, 95% credible interval [CrI] 0.93-0.99 for fibrinolytic therapy and 0.99, 95% CrI 0.95-1.05, for primary PCI). INTERPRETATION: In 2003, many patients with STEMI in Quebec were not treated within the recommended times. Delays may be reduced by reorganizing pre-and in-hospital care for patients with STEMI to expedite delivery of reperfusion therapy.
BACKGROUND: Patterns of care for acute myocardial infarction (AMI) strongly depend on the availability of on-site cardiac catheterization facilities. Although the management found at hospitals without on-site catheterization does not lead to increased mortality, little it known about its impact on resource utilization and non-fatal outcomes. METHODS: We identified all patients (n = 35,289) admitted with a first AMI in the province of Quebec between January 1, 1996 and March 31, 1999 using population-based administrative databases. Medical resource utilization and non-fatal and fatal outcomes were compared among patients admitted to hospitals with and without on-site cardiac catheterization facilities. RESULTS: Cardiac catheterization and PCI were more frequently performed among patients admitted to hospitals with catheterization facilities. However, non-invasive procedures were not used more frequently at hospitals without catheterization facilities. To the contrary, echocardiography [odds ratio (OR), 2.04; 95% confidence interval (CI), 1.93-2.16] and multi-gated acquisition imaging (OR, 1.24; 95% CI, 1.17-1.32) were used more frequently at hospitals with catheterization, and exercise treadmill testing (OR, 1.02; 95% CI, 0.91-1.15) and Sestamibi/Thallium imaging (OR, 0.93; 95% CI, 0.88-0.98) were used similarly at hospitals with and without catheterization. Use of anti-ischemic medications and frequency of emergency room and physician visits, were similar at both types of institutions. Readmission rates for AMI-related cardiac complications and mortality were also similar [adjusted hazard ratio, recurrent AMI: 1.02, 95% CI, 0.89-1.16; congestive heart failure: 1.02; 95% CI, 0.90-1.15; unstable angina: 0.93; 95% CI, 0.85-1.02; mortality: 0.99; 95% CI, 0.93-1.05)]. CONCLUSION: Although on-site availability of cardiac catheterization facilities is associated with greater use of invasive cardiac procedures, non-availability of catheterization did not translate into a higher use of non-invasive tests or have an impact on the fatal and non-fatal outcomes available for study in our administrative database.
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Open abdominal aortic aneurysm (AAA) repair is a common surgical procedure associated with high mortality rates. Our objective was to describe the use of in-hospital cardiac medical therapy among patients undergoing open AAA repair and to examine the effect of perioperative cardiac medical therapy on in-hospital mortality. We examined clinical data and in-hospital medication use among 223 patients who underwent open AAA repair at three North American hospitals, all of which used the Transition resource and cost accounting system. Medication use was described [angiotensin converting enzyme (ACE) inhibitors, aspirin, ss-blockers, and statins] within the cohort at five specific periods of time: presurgery, day of surgery, 1 day after surgery, postsurgery, and discharge. We then performed a matched case-control study where cases were defined as patients who died in-hospital. We compared medication use between cases and controls to assess its impact on in-hospital mortality. Most patients were elderly (mean age 72.5 +/- 9.8 years), 70.4% were male, and in-hospital mortality within the cohort was 10.8%. Medication use in all periods of administration was low. ss-Blocker use was highest among all classes on the day of surgery, with 20.6% of patients undergoing AAA repair receiving the medication. Less than 50% of patients received any of the medications at discharge. After adjusting for baseline differences, perioperative ACE inhibitor use showed a trend toward a protective effect [odds ratio (OR) = 0.09, 95% confidence interval (CI) 0.01-1.31, p = 0.08], and perioperative ss-blocker use was significantly associated with a decrease in mortality (OR = 0.07, 95% CI 0.01-0.87, p = 0.04). Cardiac medical therapy among patients undergoing AAA repair is low throughout all periods of hospitalization. ACE inhibitor and ss-blocker use may be associated with decreased in-hospital mortality.
Drug-eluting stents (DESs) have shown significant promise at reducing rates of restenosis and subsequent revascularization compared with bare metal stents (BMSs). The purpose of this report is to provide a systematic review of the randomized clinical trials that have evaluated the efficacy and safety of DESs. A total of 28 randomized clinical trials were identified: 21 comparing a DES (sirolimus, paclitaxel, ABT-578, actinomycin, everolimus, or 7-hexanoyltaxol) with a BMS and 7 comparing a DES with another DES (sirolimus vs paclitaxel). Early sirolimus and polymeric paclitaxel studies in low-risk populations demonstrated marked reductions in restenosis according to angiographic and clinical parameters, compared with BMSs. These promising findings led to the more recent evaluations of DESs in higher risk patients in controlled and head-to-head comparisons. In these subsequent trials, sirolimus and paclitaxel DESs continued to exceed the therapeutic potential of BMSs, with a slight but consistent angiographic advantage being observed with the sirolimus DESs.
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The American College of Cardiology/American Heart Association guidelines for exercise testing do not take a position regarding the utility of routine stress testing after coronary artery bypass grafting (CABG). Our purposes were (1) to document the patterns of use of stress testing after CABG and (2) to establish whether the choice of stress testing strategy is associated with clinical characteristics of patients. The Routine versus Selective Exercise Treadmill Testing after Coronary Artery Bypass Graft Surgery (ROSETTA-CABG) Registry is a prospective multicenter study that examined the use of stress testing after CABG among 395 patients at 16 clinical centers in 6 countries. During the 12 months after CABG, 37% of patients underwent stress testing (range across centers 0% to 100%). Among patients who underwent stress testing, 24% had a clinical indication and 76% had it as a routine follow-up. A total of 65% of stress tests involved exercise treadmill testing alone, 17% involved stress nuclear perfusion imaging, 13% involved stress echocardiographic imaging, and 5% involved other types of stress tests, such as positron emission tomographic scans. The first stress test was performed at a median of 13 weeks after CABG, with 20% of patients having second tests at a median of 28 weeks and 6% having additional tests at a median of 34 weeks. Univariate and multivariate analyses demonstrated that the chief determinant of using routine stress testing was the clinical center. In conclusion, these results suggest that there is little consensus on the appropriate use of stress testing soon after CABG. Practice patterns vary widely; poorly diagnostic tests are used routinely; and the clinical center at which the procedure is performed, rather than the clinical characteristics of the patient, determines the use of stress testing after CABG.
INTRODUCTION: Secondary prevention is needed following coronary artery bypass graft (CABG) surgery to reduce the subsequent risk of unstable angina, myocardial infarction and death. However, little research exists on the use of cardiovascular medical therapy in CABG surgery patients. The objective of the present study is to describe the use of cardiovascular medical therapy among patients discharged after CABG surgery. METHODS: The use of acetylsalicylic acid, clopidogrel, warfarin, antilipid agents, beta-blockers, calcium channel blockers, nitrates and angiotensin-converting enzyme (ACE) inhibitors was examined among 320 patients enrolled in the Routine versus Selective Exercise Treadmill Testing After Coronary Artery Bypass Graft Surgery (ROSETTA-CABG) Registry. Logistic regression identified the determinants of medication use at 12 months following CABG surgery. RESULTS: Most patients were male, hyperlipidemic and underwent CABG surgery for relief of angina symptoms. At admission, discharge and at 12 months, acetylsalicylic acid was used in 71%, 92% and 87% of cases, respectively, and some form of antiplatelet agent was used in 74%, 94% and 89% of cases, respectively. The use of antilipid agents remained constant, from 55% at admission to 57% at discharge. However, 24% of patients were not receiving antilipid agents at 12 months. The use of beta-blockers was 57% at admission, 71% at discharge and 64% at 12 months. The use of calcium channel blockers and nitrates decreased modestly from admission to discharge and remained stable at approximately 20% and 22%, respectively, at 12 months. ACE inhibitor use remained stable, from 33% at admission to 38% at 12-months. Hyperlipidemia, hypertension, obesity and pre-CABG surgery left ventricular ejection fraction less than 40% were all found to be important determinants of 12-month medication use. Importantly, the use at discharge was an important determinant of 12-month use of for each medication examined in the present study. CONCLUSIONS: The use of antilipid agents, beta-blockers and ACE inhibitors was found to be too low among post-CABG surgery patients, who are known to benefit from their use, and the use of nitrates was too high. Discharge from hospital provides a unique opportunity for physicians to modify the use of cardiovascular medical therapy among patients undergoing CABG surgery.
BACKGROUND: In many hospitals in the provinces of Quebec and Nova Scotia, as well as in some hospitals in the rest of Canada, coronary angiograms are performed and interpreted by invasive cardiologists, and are later reinterpreted and reported by radiologists. OBJECTIVE: To evaluate the value of second readings of coronary angiograms by radiologists. METHODS: Cardiology and radiology reports of a total of 160 consecutive coronary angiograms were compared from patients at three hospitals. Ten segments of the coronary tree were considered and 1582 segments were included. Agreement between cardiology and radiology interpretations was evaluated using per cent agreement, Pearson correlation and Bland-Altman limits of agreement. Agreement was calculated for each arterial segment and for each hospital. RESULTS: Excellent agreement was found between cardiology and radiology interpretations of coronary angiograms. Per cent agreement ranged from 94.9% to 100%, Pearson correlation ranged from 0.83 to 0.97 and Bland-Altman limits of agreement ranged from -18.1 to 19.4. Agreement was similar for each segment and for each hospital. Agreement remained excellent after exclusion of normal angiograms (n=348 segments), with a per cent agreement of 96.3%. Secondary analyses demonstrated a mean time delay of 13 days between angiograms and the subsequent radiology reports. CONCLUSIONS: There are minimal differences between the cardiology and radiology interpretations of coronary angiograms. Routine second reading by a radiologist may be redundant.
BACKGROUND: There is little consensus regarding the use of functional testing after coronary artery bypass graft surgery (CABG). Some physicians opt for a routine functional testing strategy, while others employ a symptom-driven strategy. OBJECTIVE: To examine the effects of routine post-CABG functional testing on the use of follow-up cardiac procedures and clinical events. METHODS: The Routine versus Selective Exercise Treadmill Testing after Coronary Artery Bypass Graft Surgery (ROSETTA-CABG) Registry is a prospective, multicenter cohort study examining the use of functional testing after CABG among 408 patients. The frequencies of functional testing, cardiac procedures, and clinical events were examined during the first 12 months following a successful CABG. RESULTS: Patients were predominantly male (80%) with a mean age of 63 +/- 10 years. During the 12-month follow up, 111 patients were observed to undergo a routine functional testing strategy, while 284 patients underwent a selective strategy. Patients undergoing routine functional testing underwent fewer follow-up cardiac catheterizations, but similar numbers of revascularization procedures (cardiac catheterizations = 0.9% vs. 8.1%; p = 0.027; percutaneous coronary intervention [PCI] = 0.9% vs. 4.6%; p = NS; repeat CABG = 0.0% vs. 0.0%; p = NS, respectively). However, clinical events were less common among patients who underwent routine functional testing including unstable angina (0.0% vs. 6.4%; p = NS), myocardial infarction (MI) (0.0% vs. 2.1%; p = NS), and death (0.9% vs. 1.4%; p = NS). The majority of clinical and procedural events occurred in the selective group who had a positive functional test (clinical events = 33%; procedural events = 40%). In contrast, no events occurred in patients in the routine group with a positive or indeterminate test, while those with a negative test had more events (6.3%) and procedures (6.3%). CONCLUSIONS: Because routine functional testing 1 year after CABG is associated with extremely low event rates, this strategy does not appear to be warranted.
BACKGROUND: Although coronary artery bypass graft surgery (CABG) is known to reduce angina, previous studies have suggested that anti-anginal medication use is not significantly reduced after CABG. However, it is unclear how functional testing results have an impact on anti-anginal medication prescription patterns. OBJECTIVES: To determine whether post-CABG functional testing results impact prescription patterns of anti-anginal medication during the 12 months after CABG. METHODS: The Routine versus Selective Exercise Treadmill Testing after Coronary Artery Bypass Graft Surgery (ROSETTA-CABG) Registry is a prospective, multicenter study. We examined anti-anginal medication use (beta blockers, calcium channel blockers and nitrates) at discharge and at 12 months post-CABG with respect to functional testing results among 392 patients. RESULTS: Among the 392 patients, 146 had at least one functional test over the 12-month follow up period. Among the 146 patients, 17% had positive functional tests, 69% had negative tests, and 14% had indeterminate tests. Both beta blocker and calcium channel blocker use did not increase from discharge to 12 months following a positive test (N = 25) (84% vs. 80%; p = NS; 16% vs. 16%; p = NS), while nitrate use increased seven-fold (4% vs. 28%; p = 0.03). However, following a negative test (N = 100), beta blocker use only decreased modestly (85% vs. 70%; p = 0.01), while both calcium channel blocker and nitrate use were unchanged (30% vs. 20%; p = NS; 4% vs. 6%; p = NS, respectively). Following an indeterminate test (N = 21), anti-anginal medication use was unchanged (p = NS for all 3 classes of medication). CONCLUSION: The use of anti-anginal medication is only modestly reduced after CABG, and functional testing results during the first year post-CABG do not have a strong impact on prescription patterns of anti-anginal agents.
BACKGROUND: Many Americans have been purchasing their medications from online Canadian pharmacies. Although it is commonly perceived that medications are less expensive in Canada than in the United States, little research has been done to quantify this difference. OBJECTIVE: To compare the prices of retail brand-name medications between Canadian Internet pharmacies and major U.S. drug chain pharmacies with online pricing. DESIGN: Cross-sectional study. SETTING: 12 Canadian Internet pharmacies and 3 major online U.S. drug chain pharmacies. MEASUREMENTS: The authors calculated the per unit and annual savings (in U.S. dollars) for an American if he or she were to buy the 44 brand-name medications most commonly purchased through the Internet from Canadian Internet pharmacies instead of from an online U.S. drug chain pharmacy. RESULTS: Americans can save a mean of approximately 24% per unit of drug if they purchase their medications from Canadian Internet pharmacies instead of from major online U.S. drug chain pharmacies. Forty-one of the 44 brand-name medications examined were less expensive in Canada. The medications offering the largest mean yearly savings were Zyprexa (olanzapine) (Eli Lilly, Indianapolis, Indiana) (1159 dollars), Actos (pioglitazone) (Eli Lilly, Indianapolis, Indiana) (852 dollars), and Nexium (esomeprazole) (AstraZeneca, Wilmington, Delaware) (772 dollars). Only 3 medications, all in the erectile dysfunction category, were more expensive in Canada. LIMITATIONS: Potential savings may vary because of temporal fluctuations in drug prices. CONCLUSIONS: Brand-name medications are often substantially less expensive when purchased from Canadian Internet pharmacies instead of from major online U.S. drug chain pharmacies.
BACKGROUND: We sought to determine whether there is a difference in in-hospital outcomes and costs for coronary artery bypass graft surgery (CABG) between the United States and Canada. METHODS: We compared the outcomes and costs of treating 12 017 consecutive patients (4698 US and 7319 Canadian patients) undergoing CABG at 5 US and 4 Canadian hospitals. Participating hospitals used the same cost accounting system to provide patient-level clinical, resource utilization, and cost-of-treatment data (excluding physicians' fees). Canadian costs were converted to US dollars using purchasing power parities. RESULTS: Compared with Canadian patients, US patients were older (mean +/- SD age, 68.0 +/- 10.4 vs 63.7 +/- 9.8 years [P<.001]), more likely to be female (27.4% vs 21.8% [P<.001]), and discharged from the hospital sooner (mean +/- SD length of stay, 8.7 +/- 0.1 vs 9.5 +/- 0.1 days [P<.001]). In-hospital costs of treatment were substantially higher in the United States than in Canada (mean +/- SD cost, dollar 20,673 +/- dollar 241 vs dollar 10,373 +/- dollar 123 [P<.001]; median, dollar 16,036 vs dollar 7880). After controlling for demographic and clinical differences, length of stay in Canada was 16.8% longer than in the United States; there was no difference in in-hospital mortality; and the cost in the United States was 82.5% higher than in Canada (P<.001). CONCLUSIONS: The in-hospital cost of CABG in the United States is substantially higher than in Canada. This difference is due to higher direct and overhead costs in US hospitals, is not explained by demographic or clinical differences, and does not lead to superior clinical outcomes.
BACKGROUND: Clinical trials have shown the benefits of statins after acute myocardial infarction (AMI). However, it is unclear whether different statins exert a similar effect in reducing the incidence of recurrent AMI and death when used in clinical practice. METHODS: We conducted a retrospective cohort study (1997-2002) to compare 5 statins using data from medical administrative databases in 3 provinces (Quebec, Ontario and British Columbia). We included patients aged 65 years and over who were discharged alive after their first AMI-related hospital stay and who began statin treatment within 90 days after discharge. The primary end point was the combined outcome of recurrent AMI or death from any cause. The secondary end point was death from any cause. Adjusted hazard ratios (HRs) for each statin compared with atorvastatin as the reference drug were estimated using Cox proportional hazards regression analysis. RESULTS: A total of 18,637 patients were prescribed atorvastatin (n = 6420), pravastatin (n = 4480), simvastatin (n = 5518), lovastatin (n = 1736) or fluvastatin (n = 483). Users of different statins showed similar baseline characteristics and patterns of statin use. The adjusted HRs (and 95% confidence intervals) for the combined outcome of AMI or death showed that each statin had similar effects when compared with atorvastatin: pravastatin 1.00 (0.90-1.11), simvastatin 1.01 (0.91-1.12), lovastatin 1.09 (0.95-1.24) and fluvastatin 1.01 (0.80-1.27). The results did not change when death alone was the end point, nor did they change after adjustment for initial daily dose or after censoring of patients who switched or stopped the initial statin treatment. INTERPRETATION: Our results suggest that, under current usage, statins are equally effective for secondary prevention in elderly patients after AMI.
BACKGROUND: Combinations of aspirin with thienopyridine derivatives (clopidogrel bisulfate or ticlopidine hydrochloride) and/or warfarin sodium are increasingly being used in various cardiac conditions. However, little is known about the bleeding risks associated with these combinations, particularly in elderly individuals at the population level. This study estimates the bleeding risks associated with combinations of aspirin, thienopyridine derivatives, and warfarin in elderly patients. METHODS: We conducted a population-based observational cohort study using linked administrative databases. A total of 21,443 elderly survivors of acute myocardial infarction between 1996 and 2000 were studied. Patients were divided into 5 groups according to drug exposure: aspirin alone, warfarin alone, aspirin plus a thienopyridine derivative (antiplatelet combination), aspirin plus warfarin (anticoagulant combination), and aspirin plus warfarin plus a thienopyridine derivative (3-drug combination). Hospitalizations for bleeding events were examined. RESULTS: Hospitalizations for bleeding were observed in 1428 patients (7%). Compared with rates of patients receiving aspirin alone (0.03 per patient-year), rates of bleeding were higher among patients receiving the antiplatelet combination (0.07 per patient-year), the anticoagulant combination (0.08 per patient-year), and the 3-drug combination (0.09 per patient-year). Compared with aspirin alone, the adjusted odds ratios (95% confidence intervals) for bleeding were 1.65 (1.02-2.73) for patients receiving the antiplatelet combination and 1.92 (1.28-2.87) for patients receiving the anticoagulant combination. Only 1 of 141 patients in the 3-drug combination group had a bleeding event. CONCLUSION: In practice, antiplatelet and anticoagulant combinations lead to modest increases in bleeding risk in elderly patients, but the overall risk is small.
The purpose of this paper is to review the randomized controlled trial (RCT) data investigating cardiac medical therapy for patients after coronary artery bypass grafting (CABG). We identified RCTs with > or =100 enrolled patients that examined the impact of cardiac medical therapy on outcomes > or =1 year after CABG. The MEDLINE database was searched for trials conducted between 1966 and 2004 on the following medications: aspirin, antilipid agents, beta-blockers, calcium channel blockers (CCBs), nitrates, and angiotensin-converting enzyme (ACE) inhibitors. Both aspirin and antilipid agents were found to reduce the progression of atherosclerosis and the occurrence of graft occlusion. Cardiovascular events were decreased with antilipid agents. In small trials, beta-blockers and CCBs failed to decrease the incidence of cardiovascular events. No RCTs examined nitrates, and one small RCT documented a reduction in cardiovascular events among patients treated with ACE inhibitors. We conclude that few RCTs have examined the efficacy of cardiac medical therapy in post-CABG patients. Based on current RCT evidence, aspirin and antilipid agents should be used routinely after CABG. However, current data do not support the use of beta-blockers, CCBs, and nitrates, and more evidence is needed regarding the use of ACE inhibitors.
In-hospital outcomes associated with abdominal aortic aneurysm (AAA) repair are well described. However, little is known about post-discharge readmission rates, lengths of stay, associated mortality, and costs. We examined 206 consecutive patients who underwent AAA repair at two American hospitals between 1998 and 2000. Index hospitalization and 6-month readmission data were extracted from a resource and cost accounting system used by both hospitals. Among the 206 patients, 183 survived until discharge (mortality rate 11.2%). Among the surviving patients, 38 (21.0%) were readmitted within 6 months. Half of the readmissions occurred within two weeks of discharge, with patients presenting with a diverse array of complications. Nonelective repair and diabetes mellitus were independent predictors of hospital readmission (OR = 2.83, 95% CI = 1.25-6.40, p = 0.01; OR = 6.60, 95% CI = 1.02-42.4, p = 0.047, respectively). For each readmission, the mean length of stay was 10.7 +/- 2.5 days and the mean cost was dollar 13,397 +/- 3,381. The cumulative number of hospital days during the 6 months post-discharge was 17.7 +/- 3.5 days for each readmitted patient and the mean per-patient total cost was dollar 23,262 +/- 5,478. The mortality rate among readmitted patients was 13.2%. Overall, readmissions following AAA repair accounted for a cost >50% over and above the cost of the readmitted patients' index hospitalization. Hospital readmissions are common during the 6 months following AAA repair. Patients who are readmitted experience long lengths of stay and high mortality rates, and their care incurs high costs.