Short and Long-term Survival Rates following Myocardial Infarction and its Predictive Factors: A Study Using National Registry Data

Samaneh Mozaffarian; Korosh Etemad; Mohammad Aghaali; Soheila Khodakarim; Sahar Sotoodeh Ghorbani; Seyed Saeed  Hashemi Nazari

doi:10.18502/jthc.v16i2.7387

Samaneh Mozaffarian School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Korosh Etemad Environmental and Occupational Hazard Control Research Center, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Mohammad Aghaali School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Soheila Khodakarim School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Sahar Sotoodeh Ghorbani School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Seyed Saeed Hashemi Nazari Prevention of Cardiovascular Disease Research Center, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

DOI: https://doi.org/10.18502/jthc.v16i2.7387

Keywords: Cox Regression; Myocardial infarction; Survival rate; Hypertension

Abstract

Background: Coronary artery disease is the most common cause of death worldwide as well as in Iran. The present study was designed to predict short and long-term survival rates after the first episode of myocardial infarction (MI).

Methods: The current research is a retrospective cohort study. The data were collected from the Myocardial Infarction Registry of Iran in a 12-month period leading to March 20, 2014. The variables analyzed included smoking status, past medical history of chronic heart disease, hypertension, diabetes, hyperlipidemia, signs and symptoms during an attack, post-MI complications during hospitalization, the occurrence of arrhythmias, the location of MI, and the place of residence. Survival rates and predictive factors were estimated by the Kaplan–Meier method, the log-rank test, and the Cox model.

Results: Totally, 21 181 patients with the first MI were studied. There were 15 328 men (72.4%), and the mean age of the study population was 62.10±13.42 years. During a 1-year period following MI, 2479 patients (11.7%) died. Overall, the survival rates at 28 days, 6 months, and 1 year were estimated to be 0.95 (95% CI: 0.95 to 0.96), 0.90 (95% CI: 0.90 to 0.91), and 0.88 (95% CI: 0.88 to 0.89). After the confounding factors were controlled, history of chronic heart disease (p<0.001), hypertension (p<0.001), and diabetes (p<0.001) had a significant relationship with an increased risk of death and history of hyperlipidemia (p<0.001) and inferior wall MI (p<0.001) had a significant relationship with a decreased risk of death.

Conclusion: The results of this study provide evidence for health policy-makers and physicians on the link between MI and its predictive factors.