Therapeutic trends in the management of patients with acute myocardial infarction (1975-1984): the Worcester Heart Attack Study

Trends in treatment and outcomes for acute myocardial infarction: 1975-1995

PURPOSE

To review the trends in treatment and survival for patients with acute myocardial infarction over the last 20 years.

MATERIAL AND METHODS

Studies were identified through MEDLINE searches and review of study bibliographies. Additional data were obtained from the Health Care Financing Administration including data from Medicare claims files (part A). Thirty-day mortality rates were calculated using Medicare data and case fatality rates from the National Hospital Discharge Survey. Published meta-analyses were used to determine treatment effects. Published studies were included if they reported the use of therapies for acute myocardial infarction at a population level. Trends in the demographic characteristics of the patients as well as infarct characteristics, medication use, and revascularization were recorded.

RESULTS

The use of acute treatments that are known to improve survival among patients with myocardial infarction has increased markedly during the last 20 years, leading to an estimated 9.6% reduction (from 27.0% to 17.4%) in 30-day mortality. After adjusting for potential interactions between therapies, the increase in use of aspirin, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, and reperfusion can explain 71% of the decrease in the 30-day age- and sex-adjusted mortality rate from 1975 to 1995. The greatest effect of a given therapy was that of aspirin, which accounted for 34% of the decrease in 30-day mortality, followed by thrombolysis (17%), primary angioplasty (10%), beta-blockers (7%), and ACE inhibitors (3%). If other treatments (such as heparin or nonprimary angioplasty), whose effects on mortality are less certain, are included, up to 90% of the decrease in 30-day mortality can be explained by changes in treatment.

CONCLUSIONS

The primary reason for the decrease in early mortality from myocardial infarction during the last 20 years appears to be increased use of effective treatments.

Need for a large randomized trial to evaluate the effects of digitalis on morbidity and mortality in congestive heart failure

Despite major advances in the prevention and treatment of cardiovascular diseases, the incidence and prevalence of congestive heart failure (CHF) have been increasing in recent years. As the average age of the population increases, the prevalence of CHF is expected to continue to increase. The number of deaths in which CHF was considered the underlying or contributing cause increased from 51,000 in 1955 to 274,000 by 1988 in the United States. Even accounting for population growth and an increase in the number of elderly, this represents a 2-fold increase. Additionally, CHF was responsible for about 643,000 hospitalizations in 1988. Digitalis is one of the drugs most commonly prescribed for CHF and has been used for greater than 200 years. In 1990, digoxin was one of the most commonly prescribed drugs in the United States, accounting for greater than 21 million prescriptions. There has been little decline in the drug's use over the last 5 years, indicating that newer treatments for CHF have not replaced the widespread use of digitalis. Despite these findings, considerable controversy surrounds the appropriateness of its role and value in treating CHF patients who are in sinus rhythm. A number of recent, uncontrolled studies have arrived at apparently contradictory conclusions concerning the effects of digitalis on mortality in postmyocardial infarction and heart failure patients. A large, double-blind, randomized, controlled clinical trial to evaluate the effects of digitalis on mortality, morbidity and quality of life is being sponsored by the National Heart, Lung, and Blood Institute in conjunction with the Department of Veterans Affairs Cooperative Studies Program.(ABSTRACT TRUNCATED AT 250 WORDS)

The antiplatelet effects of organic nitrates and related nitroso compounds in vitro and in vivo and their relevance to cardiovascular disorders

Organic nitrates, cornerstones of antianginal therapy, are believed to exert their principal anti-ischemic benefit by relaxing vascular smooth muscle. Recent evidence suggests that these compounds and related nitro(so) vasodilators are also potent platelet inhibitors. In view of the well recognized role of thrombotic events mediated by platelets in acute coronary syndromes, the antiplatelet effect of nitrates may also be of mechanistic importance in the treatment of these disorders. This review details the biochemical mechanism by which nitro(so) compounds inhibit platelet function and summarizes the in vitro and in vivo evidence that supports their antithrombotic effects.

Cardiogenic shock after acute myocardial infarction. Incidence and mortality from a community-wide perspective, 1975 to 1988

BACKGROUND

Cardiogenic shock resulting from acute myocardial infarction is a serious complication with a high mortality rate, but little is known about whether its incidence or outcome has changed over time. As part of an ongoing population-based study of acute myocardial infarction, we examined trends over time in the incidence and mortality rate of cardiogenic shock after acute myocardial infarction.

METHODS

We studied 4762 patients with acute myocardial infarction who were admitted to 16 hospitals in the Worcester, Massachusetts, metropolitan area between 1975 and 1988. We determined the incidence of and short-term and long-term mortality due to cardiogenic shock in each of six years during this study period.

RESULTS

The incidence of cardiogenic shock complicating acute myocardial infarction remained relatively constant, averaging 7.5 percent. Multivariate regression analysis that controlled for variables affecting incidence revealed significant though inconsistent temporal trends in the incidence of cardiogenic shock. As compared with the risk in 1975, the adjusted relative risk (with 95 percent confidence interval) was 0.83 (0.54 to 1.28) in 1978, 0.96 (0.63 to 1.48) in 1981, 0.68 (0.42 to 1.12) in 1984, 1.16 (0.70 to 1.92) in 1986, and 1.65 (0.99 to 2.77) in 1988. The overall in-hospital mortality rate among patients with cardiogenic shock was significantly higher than that among patients without this complication (77.7 percent vs. 13.5 percent, P less than 0.001). The in-hospital mortality among the patients with shock did not improve between 1975 (73.7 percent) and 1988 (81.7 percent). Long-term survival during the 14-year follow-up period was significantly worse among patients who survived cardiogenic shock during hospitalization than among patients who did not have shock (P less than 0.001).

CONCLUSIONS

The results of this observational, community-wide study suggest that neither the incidence nor the prognosis of cardiogenic shock resulting from acute myocardial infarction has improved over time. Both in-hospital and long-term survival remain poor for patients with this complication.

Two-year survival after myocardial infarction

We have studied 773 consecutive cases (706 individuals) with definite myocardial infarction treated in the Coronary Care Unit at Danderyd Hospital in Stockholm during the period 1984-85. Hospital mortality was 12.9% in all patients and 8.9% in patients under 70 years of age. Six hundred and six patients were discharged from the hospital and followed up for 2 years. The 2-year mortality in ischaemic heart disease was 14.4% in all patients and 9.5% in patients under 70 years of age and, including all causes of death, 20.3% and 14.6%, respectively. Our policy for medical treatment included frequent use of beta-adrenergic blocking agents, even in heart failure, and restricted use of antiarrhythmic drugs and digitalis. A short delay of admission may have been beneficial for the result of different kinds of anti-ischaemic intervention. Furthermore, a routinely performed exercise ECG before discharge and after 6 weeks, as part of a structured follow-up, has improved our ability to detect complications at an early stage and to optimize medical treatment.