Although silent myocardial infarction ( SMI ) accounts for about one-half of the total number of myocardial infarctions ( MIs ), the risk of heart failure ( HF ) among patients with silent myocardial infarction is not well established.
The purpose of a study was to examine the association of silent myocardial infarction and clinically manifested myocardial infarction ( CMI ) with heart failure, as compared with patients with no myocardial infarction.
This analysis included 9,243 participants from the ARIC ( Atherosclerosis Risk In Communities ) study who were free of cardiovascular disease at baseline ( ARIC visit 1: 1987 to 1989 ).
Silent myocardial infarction was defined as electrocardiographic evidence of myocardial infarction without manifested myocardial infarction after the baseline until ARIC visit 4 ( 1996 to 1998 ).
Heart failure events were ascertained starting from ARIC visit 4 until 2010 in individuals free of heart failure before that visit.
Between ARIC visits 1 and 4, 305 silent myocardial infarctions and 331 manifested myocardial infarctions occurred.
After ARIC visit 4 and during a median follow-up of 13.0 years, 976 heart failure events occurred.
The incidence rate of heart failure was higher in both CMI and SMI participants than in those without myocardial infarction ( incidence rates per 1,000 person-years were 30.4, 16.2, and 7.8, respectively; p less than 0.001 ).
In a model adjusted for demographics and HF risk factors, both silent myocardial infarction ( hazard ratio [ HR ]: 1.35; 95% confidence interval [ CI ]: 1.02 to 1.78 ) and manifested myocardial infarction ( HR: 2.85; 95% CI: 2.31 to 3.51 ) were associated with increased risk of heart failure compared with no myocardial infarction.
These associations were consistent in subgroups of participants stratified by several heart failure risk predictors.
However, the risk of heart failure associated with silent myocardial infarction was stronger in those younger than the median age ( 53 years ) ( HR: 1.66; 95% CI: 1.00 to 2.75 vs. HR: 1.19; 95% CI: 0.85 to 1.66, respectively; overall interaction p by myocardial infarction type less than 0.001 ).
In conclusion, silent myocardial infarction is associated with an increased risk of heart failure.
Future research is needed to examine the cost effectiveness of screening for silent myocardial infarction as part of heart failure risk assessment, and to identify preventive therapies to improve the risk of heart failure among patients with silent myocardial infarction. ( Xagena )
Qureshi WT et al, J Am Coll Cardiol. 2018; 71:1-8