Timely diagnosis and treatment of sleep apnea reduce cardiovascular sequelae in patients with myocardial infarction.

Background: The present study aimed to test if the temporal sequence between sleep apnea (SA) diagnosis and incident myocardial infarction (MI) was associated with the long-term mortality and cardiovascular event in a community-based cohort.

Methods: We retrieved data from 9,453 incident MI patients between Jan. 1st 2000 and Dec. 31st 2012 from the Taiwan National Health Insurance Research Database. The study subjects included 207 MI patients with SA (SA-MI), further stratified into 110 with pre-existing SA before MI (SA-bMI) and 96 diagnosed with SA after MI (SA-pMI). The median follow-up period was 4.2 years. Propensity-score-matched controls were selected from 9,246 non-SA MI patients (non-SA-MI). The association of SA and outcomes including all-cause mortality and major adverse cardiac and cerebrovascular events (MACCEs) were analyzed by a Cox proportional hazards model.

Results: The result showed that SA was not associated with mortality regardless of the timing of SA diagnosis. SA-pMI was associated with increased risk of MACCEs (Hazard ratio [HR]: 1.412, 95% confidence interval [CI]: 1.037~1.923, p = 0.029) including re-MI or revascularization and ischemic heart disease hospitalization. Such an association was most significant for SA diagnosed within one year after MI (HR: 2.029, 95% CI: 1.265~3.254, p = 0.003), which was not seen in patients treated with continuous positive airway pressure (CPAP).

Conclusion: The temporal sequence and the time interval between SA diagnosis and incident MI was associated with the cardiovascular events after MI, especially within one year after MI. Early assessment for the presence of SA after incident MI and early CPAP intervention may reduce the risk of further adverse cardiovascular events.