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Prognosis of acute myocardial infarction complicated by complete heart block (the Worcester Heart Attack Study)
R J Goldberg1, J C Zevallos, J Yarzebski
1Department of Medicine, University of Massachusetts Medical School, Worcester 01655.
Insights
Complete heart block (CHB) complicating acute myocardial infarction (AMI) remained stable but significantly increased mortality. Inferior wall AMI with CHB posed the highest in-hospital death risk, with no survival improvement over time.
Area of Science:
- Cardiology
- Clinical Medicine
- Epidemiology
Background:
- Complete heart block (CHB) is a serious complication of acute myocardial infarction (AMI).
- Understanding the incidence and prognostic impact of CHB in AMI patients is crucial for improving outcomes.
Purpose of the Study:
- To examine changes in CHB incidence complicating AMI over time.
- To assess the prognostic impact of CHB on in-hospital and long-term survival in AMI patients.
Main Methods:
- A community-based study of 4,762 patients with validated AMI hospitalized between 1975 and 1988.
- Analysis of CHB incidence rates and in-hospital/long-term survival.
- Multivariate regression analysis to control for confounding factors.
Main Results:
- CHB incidence remained stable at 5.8% over the 13-year study period.
- CHB was twice as common in inferior/posterior wall AMI (7.7%) versus anterior wall AMI (3.9%).
- Patients with CHB had higher in-hospital case fatality rates (adjusted risk of dying = 2.10) and this did not improve over time. Inferior wall AMI with CHB had a higher adjusted risk of dying (2.71).
Conclusions:
- CHB complicating AMI has a persistent and significant negative impact on in-hospital survival.
- Inferior wall AMI with CHB represents a particularly high-risk subgroup requiring intensive management.
- No improvement in in-hospital survival for CHB patients was observed during the study period.
Abstract:
As part of a community-based study of patients hospitalized with acute myocardial infarction (AMI) in the Worcester, Massachusetts, metropolitan area, changes over time in the incidence rates of complete heart block (CHB) complicating AMI, and the prognostic impact of CHB on the in-hospital and long-term survival of these patients were examined. In all, 4,762 patients with validated AMI hospitalized at 16 hospitals in the Worcester metropolitan area during 1975, 1978, 1981, 1984, 1986 and 1988 constituted the study sample. The incidence rates of CHB complicating AMI remained relatively stable at 5.8% over the 13-year (1975 to 1988) period studied. The incidence rates of CHB were approximately twice as high in patients with inferior/posterior wall AMI (7.7%) as in those with anterior wall AMI (3.9%). Use of a multivariate regression analysis to control for factors affecting the incidence rates of CHB revealed that patients were at highest risk for developing CHB during the latter 2 study years (1986 and 1988). Patients with AMI developing CHB had higher in-hospital case fatality rates than did those without CHB overall, as well as during each of the 6 periods studied. The in-hospital survival associated with CHB did not improve over time. After use of a multivariate regression analysis to control for additional prognostic factors, the independent effect of CHB on in-hospital prognosis remained (adjusted risk of dying = 2.10; 95% confidence intervals = 1.37, 3.21). Patients with inferior wall AMI complicated by CHB were at significantly increased risk of dying during hospitalization compared with those without CHB (adjusted risk of dying = 2.71; 95% confidence intervals = 1.60, 4.59).(ABSTRACT TRUNCATED AT 250 WORDS)