BACKGROUND: The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for exercise testing suggest that only selected groups of high-risk patients should undergo routine functional testing after percutaneous transluminal coronary angioplasty (PTCA) for the detection of restenosis. OBJECTIVES: Our purpose was (1) to document the patterns of use of post-PTCA functional testing and (2) to determine whether the choice of functional testing strategy is related to clinical characteristics of patients or whether physicians use a similar strategy for all their patients. METHODS: The Routine Versus Selective Exercise Treadmill Testing After Angioplasty (ROSETTA) Registry is a prospective study examining the use of functional testing among 788 patients at 13 centers in 5 countries. RESULTS: During the 6-month period after a successful PTCA, 49% of patients underwent functional testing (range among centers 10%-81%). Among patients who underwent functional testing, 39% had a clinical indication and 61% had functional testing as a routine follow-up. The first functional test was performed a median of 7 weeks after PTCA, with 13% of patients having second tests at a median of 14 weeks and 4% having additional tests at a median of 20 weeks. Univariate and multivariate analyses demonstrated that the chief determinant of the use of routine functional testing was clinical center. Aside from age (P <.0001), no baseline clinical or procedural characteristics were consistently associated with the use of routine functional testing after PTCA. CONCLUSIONS: Physicians do not appear to be adhering to the ACC/AHA guidelines for exercise testing regarding the routine use of post-PTCA functional testing. None of the clinical characteristics identified by the ACC/AHA guidelines were associated with the routine use of post-PTCA functional testing, and the primary determinant of functional testing was the location of the center at which the patient had the PTCA.

Angioplasty, Balloon, Coronary↗

PubMed2001

Effects of cocaine on the coronary arteries.

BACKGROUND: A number of studies have documented myocardial ischemia and infarction associated with cocaine use. Mismatch between myocardial oxygen supply and demand from cocaine-induced vasoconstriction and increased myocardial workload are often invoked as the major postulated mechanism by which cocaine induces myocardial ischemia. This article reviews the literature studying the effects produced by cocaine on the coronary arteries to provide insight into the various pathophysiologic mechanisms by which cocaine triggers acute cardiac ischemia or infarction. METHODS: We reviewed the published literature describing the effects of cocaine on the coronary arteries. A MEDLINE search of English language articles published between 1985 and 2000 was performed. Key words included coronary arteries, coronary vasoconstriction, vasospasm, coronary vasodilation, cardiac vasculature, myocardial ischemia, platelets, thrombosis, and cocaine. Both animal and human studies were included. The bibliographies of identified articles were also explored for additional sources of information. RESULTS: A recreational dose of cocaine increases the heart rate by approximately 30 beats/min. It also increases the blood pressure by 20/10 mm Hg. These increases are modest, are equivalent to mild exercise, and are not believed to be sufficient to result in myocardial ischemia in the majority of cases. Animal and human studies have documented cocaine-induced early coronary artery vasodilation as shown by a decrease in coronary perfusion pressure ranging from 13% to 68%. This was followed by a more sustained vasoconstriction demonstrated by a decrease in epicardial coronary artery diameter ranging from 5% to 30% with various doses of cocaine by various methods of administration. These changes alone are also an unlikely explanation for cocaine-induced myocardial ischemia. Therefore neither increases in myocardial workload nor hemodynamic changes are sufficient to explain cocaine-induced myocardial ischemia. However, evidence also exists that cocaine activates platelets and promotes thrombosis, resulting in intracoronary thrombus formation. Cocaine may also promote premature and more severe coronary atherosclerosis. CONCLUSION: The etiology of cocaine-induced myocardial ischemia is complex and is likely to be multifactorial. It appears to be the result of coronary artery vasoconstriction, intracoronary thrombosis, and accelerated atherosclerosis.

Animals↗

PubMed2001

Coronary stenting in diabetic patients: Results from the ROSETTA registry.

OBJECTIVE: Diabetes mellitus is associated with high rates of restenosis and adverse outcomes after percutaneous transluminal coronary angioplasty (PTCA). It is unclear whether coronary stenting reduces adverse events in diabetic patients after PTCA. Our purpose was to determine whether coronary stenting improves clinical event rates in diabetic patients after PTCA. METHODS: The Routine Versus Selective Exercise Treadmill Testing After Angioplasty (ROSETTA) registry was a prospective multicenter observational study examining functional testing and adverse outcomes after successful PTCA. RESULTS: Among the 791 patients enrolled, 180 were diabetic. A total of 90 diabetics received stents while the remaining 90 patients did not. Baseline clinical characteristics were similar between the 2 groups of patients. However, patients with stents were more likely to have complex lesions, whereas those without stents were more likely to undergo atherectomy and have greater residual coronary stenosis. At 6-month follow-up, the composite end point defined as cardiac death, unstable angina, myocardial infarction, need for repeat PTCA, or coronary artery bypass graft surgery (CABG) occurred in 25.0% of stented and 22.2% of nonstented diabetic patients (P not significant [NS]). A multivariate logistic regression analysis showed that coronary stenting was not associated with a reduced incidence of the composite end point among diabetic patients (odds ratio 0.97, 95% CI 0.46-2.05, P NS). CONCLUSION: Coronary stenting does not improve clinical event rates in diabetic patients after PTCA.

Angioplasty, Balloon, Coronary↗

PubMed2001

Comparison of the mineral content of tap water and bottled waters.

OBJECTIVES: Because of growing concern that constituents of drinking water may have adverse health effects, consumption of tap water in North America has decreased and consumption of bottled water has increased. Our objectives were to 1) determine whether North American tap water contains clinically important levels of calcium (Ca2+), magnesium (Mg2+), and sodium (Na+) and 2) determine whether differences in mineral content of tap water and commercially available bottled waters are clinically important. DESIGN: We obtained mineral analysis reports from municipal water authorities of 21 major North American cities. Mineral content of tap water was compared with published data regarding commercially available bottled waters and with dietary reference intakes (DRIs). MEASUREMENTS AND MAIN RESULTS: Mineral levels varied among tap water sources in North America and among bottled waters. European bottled waters generally contained higher mineral levels than North American tap water sources and North American bottled waters. For half of the tap water sources we examined, adults may fulfill between 8% and 16% of their Ca2+ DRI and between 6% and 31% of their Mg2+ DRI by drinking 2 liters per day. One liter of most moderate mineralization European bottled waters contained between 20% and 58% of the Ca2+ DRI and between 16% and 41% of the Mg2+ DRI in adults. High mineralization bottled waters often contained up to half of the maximum recommended daily intake of Na+. CONCLUSION: Drinking water sources available to North Americans may contain high levels of Ca2+, Mg2+, and Na+ and may provide clinically important portions of the recommended dietary intake of these minerals. Physicians should encourage patients to check the mineral content of their drinking water, whether tap or bottled, and choose water most appropriate for their needs.

Beverages↗

PubMed2001

Discharge prescriptions following admission for acute myocardial infarction at tertiary care and community hospitals in Quebec.

BACKGROUND: Many physicians are not adhering to the recommendations found in evidence-based guidelines for the treatment of acute myocardial infarction (AMI). Physicians who practise in tertiary care settings may show better adherence to guideline recommendations than physicians who practise in other settings. OBJECTIVE: To determine whether there is an association between the practice setting of admission for AMI and discharge prescriptions for cardiac drugs recommended in evidence-based guidelines. PATIENTS AND METHODS: Discharge prescription data from a prospective cohort of patients with AMI admitted at five tertiary care (n=250) and five community hospitals (n=331) in Quebec from December 1996 to November 1998 were examined. RESULTS: The proportions of patients who were prescribed recommended drugs at tertiary care hospitals compared with those at community hospitals were as follows: beta-blockers (78% versus 74%, respectively; 95% CI around the difference - 4% to 11%), lipid-lowering drugs (45% versus 39%, respectively; 95% CI - 2% to 15%) and angiotensin-converting enzyme (ACE) inhibitors (44% versus 57%, respectively; 95% CI - 22% to - 5%). In adjusted analyses, practice setting was not associated with the prescription of beta-blockers (odds ratio [OR] for tertiary care 1.36; 95% CI 0.82 to 2.24) or lipid-lowering drugs (OR for tertiary care 1.06; 95% CI 0.67 to 1.68). However, tertiary care admission reduced the likelihood of ACE inhibitor prescription (OR 0.50; 95% CI 0.32 to 0.77). This association may have been due to the increased likelihood of ACE inhibitor prescription for patients with hypertension at community hospitals (OR 2.13; 95% CI 1.23 to 3.67). The results also showed that older patients were less likely to be prescribed beta-blockers or lipid-lowering drugs, women were less likely to be prescribed beta-blockers and patients with diabetes mellitus were less likely to be prescribed lipid-lowering drugs (OR 0.45; 95% CI 0.23 to 0.89). CONCLUSION: No strong association was found between the practice setting of admission for AMI and discharge prescriptions for cardiac drugs recommended in evidence-based guidelines. Prescription rates for recommended drugs were high, yet results suggest that there is room for improvement with regard to patients with diabetes, women and older patients.

Adrenergic Antagonists↗

PubMed2001

Functional testing for the detection of restenosis after percutaneous transluminal coronary angioplasty: a meta-analysis.

BACKGROUND: A number of studies have examined the ability of functional testing to detect restenosis after percutaneous transluminal coronary angioplasty (PTCA). However, a meta-analysis of these studies has not been performed. OBJECTIVES: To pool the results of studies examining the diagnostic abilities of exercise treadmill testing (ETT), stress nuclear imaging and stress echocardiographic imaging at six months to detect post-PTCA restenosis. The secondary objective was to examine, through the use of a theoretical model, the impact of stenting on the yield of post-PTCA functional testing. PATIENTS AND METHODS: A MEDLINE search was conducted to identify studies examining post-PTCA functional testing for the diagnosis of restenosis. The English-language literature was examined for the years 1975 to 2000. Appropriate articles were identified, and their references were examined to identify additional studies. The sensitivities and specificities of these studies were then pooled and Bayes' theorem was used to examine the effect of stenting on the diagnostic abilities of post-PTCA functional testing. RESULTS: A pooled analysis showed that ETT alone has a poor sensitivity (46%, 95% CI 33% to 58%) and a moderate specificity (77%, 95% CI 67% to 86%) for the identification of post-PTCA restenosis. The use of nuclear imaging increases the sensitivity (87%, 95% CI 74% to 100%) and the specificity (78%, 95% CI 74% to 81%). Echocardiographic imaging also increases both sensitivity (63%, 95% CI 15% to 100%) and specificity (87%, 95% CI 72% to 100%). The positive likelihood ratios for ETT alone, nuclear imaging and echocardiographic imaging were calculated to be 1.94, 3.93 and 4.94, respectively. Conversely, the negative likelihood ratios were calculated to be 0.71, 0.16 and 0.43, respectively. As restenosis rates decline from 30% to 10%, the false positive rate of stress imaging increases from 37% to 77%. CONCLUSIONS: ETT alone is poorly diagnostic of post-PTCA restenosis, while stress nuclear and stress echocardiographic imaging perform better. However, the value of routine post-PTCA functional testing to detect restenosis is declining because restenosis rates are decreasing.

Angioplasty, Balloon, Coronary↗

PubMed2001

Screening for abdominal aortic aneurysms during cardiac catheterization.

BACKGROUND: Many authorities advocate routine screening for abdominal aortic aneurysms (AAA). Patients undergoing cardiac catheterization often have risk factors for AAA. The purpose of this study was to evaluate the clinical utility of screening for AAA during cardiac catheterization. METHODS: We prospectively examined the abdominal aorta in 127 patients undergoing diagnostic cardiac catheterization. Panning down during left ventriculography was the primary method for imaging the abdominal aorta. However, if there was difficulty advancing the catheter into the abdominal aorta, a formal postero-anterior abdominal aortogram was obtained. Off-line analysis of aortic morphology and diameters was performed. RESULTS: We achieved adequate visualization of the abdominal aorta in 99 of 127 patients. Mean age was 67 years; 75% were male. Risk factors for AAA were common, and included: history of smoking (88%); angina (84%); hypertension (57%); hyperlipidemia (52%); previous myocardial infarction (39%); diabetes mellitus (30%); obesity (21%); congestive heart failure (17%); presence of peripheral vascular disease (14%); and previous peripheral vascular procedures (12%). Panning down during left ventriculography was performed in 89% of cases in the 30 degrees right anterior oblique position. Previously undiagnosed, asymptomatic abdominal aortic aneurysms were found in 8 of 99 patients (8%). The mean intraluminal aneurysmal diameter was 2.8 +/- 1.1 cm and the mean length was 5.4 +/- 1.8 cm. Abdominal ultrasonography was performed in 7 of these cases (1 patient refused), and the mean diameter measured was 3.8 +/- 1.4 cm. Peripheral vascular disease, previous peripheral vascular surgery and difficulty advancing the catheter during the procedure were associated by univariate analysis with the presence of AAA. Multivariate analysis demonstrated that difficulty threading the catheter was the only independent predictor of the presence of AAA (odds ratio = 11.1; 95% confidence interval = 4.6-26.6; p = 0.007). CONCLUSION: Undiagnosed abdominal aortic aneurysms can be identified during routine examination of the abdominal aorta during cardiac catheterization. Because screening for AAA during cardiac catheterization is inexpensive and easily performed, it should be a routine part of the examination.

Adult↗

PubMed2001

Results of a routine exercise treadmill testing strategy early after percutaneous transluminal coronary angioplasty.

BACKGROUND: Some physicians use routine exercise treadmill testing early after percutaneous transluminal coronary angioplasty (PTCA), yet there have been few prospective studies examining the results of such a functional testing strategy. OBJECTIVES: To examine the results of a routine post-PTCA exercise treadmill testing strategy, and to explore the impact of such a strategy on follow-up functional tests and cardiac procedures. PATIENTS AND METHODS: Functional test results were examined from a cohort of 226 patients who underwent PTCA at a single institution in which a routine functional testing strategy is used. Tests were defined as 'routine' if they were performed solely because the patient had a prior PTCA. Tests were defined as 'selective' if they were done for a clinical indication or if there was no functional testing during the six-month follow-up. RESULTS: A total of 183 patients (81%) underwent at least one functional test during the six-month period after PTCA. Of these patients, 150 (82%) underwent routine functional testing, the majority (73%) of which were exercise treadmill tests. Sixty-seven per cent of patients who had routine functional testing had their first functional test less than seven weeks after their PTCA. Most routine exercise treadmill tests were found to be electrically or clinically indeterminate (46%), but a substantial number were either electrically or clinically positive (28%), or electrically and clinically negative (39%). Of patients who had electrically or clinically positive routine tests, 57% had repeat functional testing and 23% had repeat revascularization. Of patients who had electrically and clinically negative tests, 53% had repeat functional testing and 10% had repeat revascularization. Of the patients who had electrically or clinically indeterminate tests, 53% had repeat functional testing and 14% had repeat revascularization. The rate of clinical events was less than 4%, irrespective of the results of the exercise treadmill tests. CONCLUSIONS: Routine exercise treadmill testing early after PTCA is associated with a low clinical yield. Most routine exercise treadmill testing results in indeterminate and negative tests, which often lead to more functional tests with little difference in clinical outcome. These results call into question the use of a routine post-PTCA functional testing strategy.

Angioplasty, Balloon, Coronary↗

PubMed2000

Changes in the treatment and outcomes of acute myocardial infarction in Quebec, 1988-1995.

BACKGROUND: Few studies have reported population-based information on the treatment trends and outcomes of patients who have had an acute myocardial infarction (AMI). We therefore examined patterns of care and outcomes for AMI patients in Quebec, Canada, between 1988 and 1995. METHODS: Longitudinal data files of hospital admissions in Quebec (Med-Echo database) and inpatient and outpatient services (Régie de l'Assurance Maladie du Québec database) were used to construct cohorts of all AMI patients in the province between 1988 and 1995. Temporal trends in the use of cardiac procedures after an AMI, discharge prescriptions and mortality rates were examined. RESULTS: Between 1988 and 1995 the age- and sex-adjusted rates of AMI in the Quebec population declined (148 per 100,000 in 1988 to 137 per 100,000 in 1995). The use of intensive cardiac procedures increased in the same period; the 1-year cumulative incidence rate of catheterization increased from 28% in 1988 to 31% in 1994, that of angioplasty rose from 8% to 15% and that of coronary artery bypass surgery from 6% to 8%. Prescriptions for ASA, beta-blockers, lipid-lowering agents and angiotensin-converting enzyme inhibitors increased, and prescriptions for nitrates and calcium antagonists decreased. These temporal changes were paralleled by a decrease in mortality rates post-AMI. All-cause 1-year cumulative incidence mortality rates decreased from 23% in 1988 to 19% in 1994. INTERPRETATION: The decrease in AMI-related mortality in Quebec between 1988 and 1995 may be linked to changes in treatment strategies (i.e., increased use of cardiac surgical procedures and medications shown to increase survival).

Age Factors↗

PubMed2000

Identification and management of patients with failed thrombolysis after acute myocardial infarction.

Explore the source record for details and available documents.

Algorithms↗

PubMed2000

Amiodarone to prevent recurrence of atrial fibrillation. Canadian Trial of Atrial Fibrillation Investigators.

BACKGROUND: The restoration and maintenance of sinus rhythm is a desirable goal in patients with atrial fibrillation, because the prevention of recurrences can improve cardiac function and relieve symptoms. Uncontrolled studies have suggested that amiodarone in low doses may be more effective and safer than other agents in preventing recurrence, but this agent has not been tested in a large, randomized trial. METHODS: We undertook a prospective, multicenter trial to test the hypothesis that low doses of amiodarone would be more efficacious in preventing recurrent atrial fibrillation than therapy with sotalol or propafenone. We randomly assigned patients who had had at least one episode of atrial fibrillation within the previous six months to amiodarone or to sotalol or propafenone, given in an open-label fashion. The patients in the group assigned to sotalol or propafenone underwent a second randomization to determine whether they would receive sotalol or propafenone first; if the first drug was unsuccessful the second agent was prescribed. Loading doses of the drugs were administered and electrical cardioversion was performed (if necessary) within 21 days after randomization for all patients in both groups. The follow-up period began 21 days after randomization. The primary end point was the length of time to a first recurrence of atrial fibrillation. RESULTS: Of the 403 patients in the study, 201 were assigned to amiodarone and 202 to either sotalol (101 patients) or propafenone (101 patients). After a mean of 16 months of follow-up, 71 of the patients who were assigned to amiodarone (35 percent) and 127 of those who were assigned to sotalol or propafenone (63 percent) had a recurrence of atrial fibrillation (P<0.001). Adverse events requiring the discontinuation of drug therapy occurred in 18 percent of the patients receiving amiodarone, as compared with 11 percent of those treated with sotalol or propafenone (P=0.06). CONCLUSIONS: Amiodarone is more effective than sotalol or propafenone for the prevention of recurrences of atrial fibrillation.

Aged↗

PubMed2000

Functional testing after percutaneous transluminal coronary angioplasty in Canada and the United States: a survey of practice patterns.

BACKGROUND: Authorities recommend various strategies to identify restenosis in patients who have undergone percutaneous transluminal coronary angioplasty (PTCA). Some authorities recommend a routine functional testing strategy, while others recommend a clinically driven strategy. MATERIALS AND METHODS: To examine the patterns of use of post-PTCA functional testing, 89 directors of cardiac catheterization laboratories in Canada and the United States were surveyed. RESULTS: Demographic characteristics of the Canadian and American respondents were similar, including median age (43 and 45 years, respectively) and median number of PTCAs performed each year (200 each). Canadians were more likely to employ a routine functional testing strategy than Americans (62% versus 38%), while Americans were more likely to employ stress imaging studies than Canadians (49% versus 35%). Overall, close to half (44%) of all the cardiologists employed a routine functional testing strategy. Physicians who employed a routine functional testing strategy performed the first functional test a median of three months after PTCA and the second a median of six months after PTCA. Both Canadian and American cardiologists tended to underestimate the incidence of restenosis after PTCA (33% without a stent and 18% with a stent) and to overestimate the sensitivity of exercise treadmill testing for the detection of restenosis (63%). CONCLUSIONS: The use of functional testing after PTCA varies widely. Canadian cardiologists are more likely to employ a routine functional testing strategy than American cardiologists. Close to half of the cardiologists surveyed employed a routine functional testing strategy. These results indicate that there is little consensus regarding the use of functional testing after PTCA.

Adult↗

PubMed1999

Reuse of catheters for percutaneous transluminal coronary angioplasty: effects on procedure time and clinical outcomes.

In July 1996, because of concern regarding the possible transmission of Creutzfeldt-Jakob disease, the province of Quebec stopped the reuse of percutaneous transluminal coronary angioplasty (PTCA) catheters. Prior to this time, PTCA balloon catheters were used a maximum of four times and guide catheters a maximum of two times in the cardiac catheterization laboratory at our institution. After this time, only new catheters were used. In order to examine the effects of catheter reuse on duration of PTCA procedures and clinical outcomes, we compared 53 consecutive patients undergoing PTCA prior to 21 July 1996 with 54 consecutive patients undergoing PTCA after that time. A total of 81 men and 26 women underwent PTCA (average age, 64 +/- 12 years). There were no significant differences between the single-use and reuse groups with respect to baseline characteristics. There were also no significant differences in the numbers of PTCA catheters used (97 vs. 103, P = NS) or angiographic success rates (88% vs. 83%, P = NS). There was a trend for total procedure time and fluoroscopy time to be slightly longer for single-use compared with reuse cases (49.2 vs. 45.7 min and 19.7 vs. 16.8 min, respectively; P = NS for both comparisons). However, after controlling for case severity and the use of stents, there were no significant differences in total procedure time or fluoroscopy time between the two groups. We found little evidence to suggest that the reuse of PTCA catheters is associated with longer total procedure time or fluoroscopy time. We conclude that if catheter reuse is not found to be associated with infectious disease transmission, its widespread use should be considered. Cathet. Cardiovasc. Intervent. 48:54-60, 1999.

Aged↗