Prevalence of influenza and other acute respiratory illnesses in
patients with acute myocardial infarction in Bangladesh: a
cross-sectional study
Abstract
Background: Several studies imply that influenza and other respiratory
illness could lead to acute myocardial infarction (AMI), but data from
low-income countries are scarce. We investigated the prevalence of
recent respiratory illnesses and confirmed influenza in AMI patients,
while also exploring their relationship with infarction severity as
defined by ST-elevation MI (STEMI) or high troponin levels. Methods:
This cross-sectional study, held at a Dhaka tertiary hospital from May
2017 to October 2018, involved AMI inpatients. The study examined
self-reported clinical respiratory illnesses (CRI) in the week before
AMI onset and confirmed influenza using baseline qRT-PCR. Results: Of
744 patients, 11.3% reported a recent CRI, most prominently during the
2017 influenza season (35.7%). qRT-PCR testing found evidence of
influenza in 1.5% of 546 patients, with all positives among STEMI
cases. Frequencies of CRI were higher in patients with STEMI and in
those with high troponin levels, although these associations were not
statistically significant after adjusting for other variables. The risk
of STEMI was significantly greater during influenza seasons in
unadjusted analysis (RR: 1.09, 95% CI: 1.02- 1.18), however, this
relationship was not significant in the adjusted analysis (aRR: 1.03,
95% CI: 0.91- 1.16). Conclusions: In Bangladesh, many AMI patients had
a recent respiratory illness history, with some showing evidence of
influenza. However, these illnesses showed no significant relationship
to AMI severity. Further research is needed to understand these
associations better and to investigate the potential benefits of
infection control measures and influenza vaccinations in reducing AMI
incidence.