Late outcome after percutaneous transluminal coronary angioplasty during acute myocardial infarction

Age and lack of beta-blocker therapy are associated with increased long-term mortality after primary coronary angioplasty for acute myocardial infarction

BACKGROUND

Few studies have examined the long-term outcome of primary PTCA for acute myocardial infarction, especially in thrombolysis-eligible patients.

METHODS

Retrospective analysis of a consecutive cohort of 228 patients treated with primary angioplasty for ST-segment elevation myocardial infarction, less than 6 h after symptom onset, of whom 203 were discharged alive and had long-term follow-up.

RESULTS

With an average follow-up of 497+/-40 days, actuarial survival rates were 94.4+/-0.02 and 86.8+/-0.06% at 2 and 4 years, respectively. Multivariate analysis showed that lack of beta-blocker therapy at discharge (RR 6.5 and 95% CI: 1.97-21.47) and age (RR 1.09 per year and 95% CI: 1.03-1.16), but not left ventricular ejection fraction were the two independent predictors of late mortality.

CONCLUSIONS

In thrombolysis-eligible patients treated with primary PCI and discharged alive, reinfarction and mortality rates are low. It appears particularly important to enforce prescription of beta-blockers at discharge is an important goal in this population.

Effects of exercise training on the heart rate variability and QT dispersion of patients with acute myocardial infarction

Heart rate variability (HRV) reflects the autonomic tone of the heart, and QT dispersion reflects the regional inhomogeneity of ventricular repolarization. The purpose of the present study was to determine the effects of early exercise training on HRV and QT dispersion in patients with acute myocardial infarction (AMI). Forty patients (mean age: 59 years) with AMI were randomized to training rehabilitation (group Tr, n=20) or conventional rehabilitation (group C, n=20). Two weeks after AMI, group Tr underwent 10 min of exercise using a bicycle ergometer (80% of anaerobic threshold) twice a day. At the end of the second and fourth weeks, 12-lead and 24-h Holter ECGs were recorded. QT intervals were measured and corrected using Bazett's formula (QTc), and QTc dispersion (QTcd) was defined as the difference between maximum and minimum QTc. HRV was accessed by the high-frequency component (HF: 0.15-0.40 Hz) of the HRV power spectrum (parasympathetic activity) and the ratio of low frequency (0.04-0.15 Hz) to HF (L/H ratio: sympathetic activity). In group Tr, HF increased (82.5 to 131.1 ms2), the L/H ratio decreased (3.9 to 2.6), and QTcd decreased (77.2 to 57.2 ms). In group C, none of the indices changed. It was concluded that early exercise training improves sympathovagal balance and decreases QTcd, and may reduce the arrhythmogenic substrate following AMI.

Sulfonylurea drugs increase early mortality in patients with diabetes mellitus after direct angioplasty for acute myocardial infarction

OBJECTIVES

The purpose of this study was to examine the impact of sulfonylurea drug use on outcome in diabetic patients undergoing direct coronary angioplasty for acute myocardial infarction.

BACKGROUND

Sulfonylurea drugs impair ischemic preconditioning. Whether sulfonylurea drugs affect outcome adversely in diabetic patients undergoing direct angioplasty for acute myocardial infarction is unknown.

METHODS

Clinical outcomes after direct balloon angioplasty for acute myocardial infarction were evaluated in 67 diabetic patients taking oral sulfonylurea drugs and 118 diabetic patients not taking these drugs.

RESULTS

Hospital mortality was significantly higher among diabetics treated with sulfonylurea drugs at the time of myocardial infarction (24% vs. 11%). Univariate analysis identified sulfonylurea drug, age, ventricular function, ejection fraction less than 40%, prior bypass surgery and congestive heart failure as correlates of increased in-hospital mortality. Logistic regression found sulfonylurea drug use (odds ratio 2.77, p=0.017) to be independently associated with early mortality. Congestive heart failure, but not sulfonylurea drug use, was associated with an increased incidence of in-hospital ventricular arrhythmias. Congestive heart failure, prior bypass surgery and female gender, but not sulfonylurea drug use, were associated with late adverse events.

CONCLUSIONS

Sulfonylurea drug use is associated with an increased risk of in-hospital mortality among diabetic patients undergoing coronary angioplasty for acute myocardial infarction. This early risk is not explained by an increase in ventricular arrhythmias, but may reflect deleterious effects of sulfonylurea drugs on myocardial tolerance for ischemia and reperfusion. For surviving patients sulfonylurea drug use is not associated with an increased risk of serious late adverse events.

A clinical trial comparing primary stenting of the infarct-related artery with optimal primary angioplasty for acute myocardial infarction: results from the Florence Randomized Elective Stenting in Acute Coronary Occlusions (FRESCO) trial

OBJECTIVES

This study sought to compare stenting of the primary infarct-related artery (IRA) with optimal primary percutaneous transluminal coronary angioplasty (PTCA) with respect to clinical and angiographic outcomes of patients with an acute myocardial infarction.

BACKGROUND

Early and late restenosis or reocclusion of the IRA after successful primary PTCA significantly contributes to increased patient morbidity and mortality. Coronary stenting results in a lower rate of angiographic and clinical restenosis than standard PTCA in patients with angina and with previously untreated, noncomplex lesions.

METHODS

After successful primary PTCA, 150 patients were randomly assigned to elective stenting or no further intervention. The primary end point of the trial was a composite end point, defined as death, reinfarction or repeat target vessel revascularization as a consequence of recurrent ischemia within 6 months of randomization. The secondary end point was angiographic evidence of restenosis or reocclusion at 6 months after randomization.

RESULTS

Stenting of the IRA was successful in all patients randomized to stent treatment. At 6 months, the incidence of the primary end point was 9% in the stent group and 28% in the PTCA group (p=0.003); the incidence of restenosis or reocclusion was 17% in the stent group and 43% in the PTCA group (p=0.001).

CONCLUSIONS

Primary stenting of the IRA, compared with optimal primary angioplasty, results in a lower rate of major adverse events related to recurrent ischemia and a lower rate of angiographically detected restenosis or reocclusion of the IRA.

Effectiveness and cost effectiveness of single bolus treatment with abciximab (Reo Pro) in preventing restenosis following percutaneous transluminal coronary angioplasty in high risk patients

OBJECTIVE

To assess the clinical effectiveness and cost effectiveness of abciximab in preventing restenosis after percutaneous transluminal coronary angioplasty (PTCA).

DESIGN

Data from a previous study, the EPIC trial, were used because only this trial was able to provide event data capable of constructing a cost effectiveness analysis over six months. All other study data reviewed supported the findings of the EPIC trial. To provide indicative results on long term health outcomes, survival and event-free survival were extrapolated using US epidemiological data in a Markov modelling process.

SETTING AND PATIENTS

Patients who were at high risk for ischaemic complications after PTCA, treated in the standard manner.

INTERVENTIONS

Abciximab was added to the regimen of intravenous heparin and aspirin.

RESULTS

The EPIC study (n = 2099) indicated an 8.1% absolute reduction in serious cardiovascular events (95% confidence interval 3.1% to 12.7%) and a 23% relative risk reduction (p = 0.001). Based on the six month trial period, the additional cost per patient free from a serious event (Australian dollars) is $13,012 and for a special risk/benefit measure of outcome, the additional cost is $14,243. Epidemiological data support extended survival and ischaemic event-free survival with clinically successful PTCA. The results of the modelled analysis indicate a cost per additional life-year gained of $5547 and a cost per additional year event-free of $4285.

CONCLUSIONS

At up to six months abciximab offers improvements in clinically important outcomes. A modelling exercise explores and highlights the likelihood of significant long term health benefits. The analysis provides information for decision makers and funders to consider the value for money of abciximab.

Projected cost-effectiveness of primary angioplasty for acute myocardial infarction

OBJECTIVES

This study sought to evaluate the cost-effectiveness of primary angioplasty for acute myocardial infarction under varying assumptions about effectiveness, existing facilities and staffing and volume of services.

BACKGROUND

Primary angioplasty for acute myocardial infarction has reduced mortality in some studies, but its actual effectiveness may vary, and most U.S. hospitals do not have cardiac catheterization laboratories. Projections of cost-effectiveness in various settings are needed for decisions about adoption.

METHODS

We created a decision analytic model to compare three policies: primary angioplasty, intravenous thrombolysis and no intervention. Probabilities of health outcomes were taken from randomized trials (base case efficacy assumptions) and community-based studies (effectiveness assumptions). The base case analysis assumed that a hospital with an existing laboratory with night/weekend staffing coverage admitted 200 patients with a myocardial infarction annually. In alternative scenarios, a new laboratory was built, and its capacity for elective procedures was either 1) needed or 2) redundant with existing laboratories.

RESULTS

Under base case efficacy assumptions, primary angioplasty resulted in cost savings compared with thrombolysis and had a cost of $12,000/quality-adjusted life-year (QALY) saved compared with no intervention. In sensitivity analyses, when there was an existing cardiac catheterization laboratory at a hospital with > or = 200 patients with a myocardial infarction annually, primary angioplasty had a cost of < $30,000/QALY saved under a wide range of assumptions. However, the cost/QALY saved increased sharply under effectiveness assumptions when the hospital had < 150 patients with a myocardial infarction annually or when a redundant laboratory was built.

CONCLUSIONS

At hospitals with an existing cardiac catheterization laboratory, primary angioplasty for acute myocardial infarction would be cost-effective relative to other medical interventions under a wide range of assumptions. The procedure's relative cost-ineffectiveness at low volumes or redundant laboratories supports regionalization of cardiac services in urban areas. However, approaches to overcoming competitive barriers and close monitoring of outcomes and costs will be needed.

Primary coronary angioplasty in acute myocardial infarction

It is well established that recanalisation of the infarct-related artery is of great benefit in the early hours after acute myocardial infarction. This can be achieved by the use of thrombolytic agents and/or by percutaneous transluminal coronary angioplasty (PTCA). This article reviews data on the role of primary PTCA and summarises current opinion on its use.

Primary angioplasty and thrombolysis for acute myocardial infarction: an evidence summary

Coronary angioplasty is being increasingly used as the primary treatment for patients with acute myocardial infarction, but controversy remains over its potential adoption in preference to thrombolysis as standard care. This report summarizes the published evidence on health outcomes after primary angioplasty compared with thrombolysis or no intervention for patients with acute myocardial infarction. The data tables presented provide the scientific groundwork to assist physicians and other policy-makers in deciding which interventions to provide for broad populations of patients.

Emergency primary coronary angioplasty in patients with acute myocardial infarction who are unsuitable for intravenous thrombolysis

Intravenous thrombolytic therapy is now accepted as the standard method of achieving coronary reperfusion in patients with acute myocardial infarction. There are several important limitations. Primary percutaneous transluminal coronary angioplasty is an attractive method for reopening occluded coronary arteries. Between 1986 and 1993, 14 patients in whom there was an absolute contraindication to thrombolysis underwent emergency coronary angioplasty as the primary treatment for acute myocardial infarction. Coronary artery patency was restored in 13/14 (93%). One patient died in hospital. The median follow-up was one year. One patient suffered a further myocardial infarction and one patient required coronary artery bypass surgery at follow-up. Emergency coronary angioplasty services should be developed to treat those patients in whom there is a contraindication to thromboloysis.