Risk for thrombotic events higher after respiratory infections needing hospitalization

Being hospitalized for respiratory infections heightens the risk of myocardial infarction (MI) and venous thromboembolism (VTE), especially in the first 30 days after discharge, a recent study has found.

The study included 5,261,068 patients discharged after a respiratory infection who were enrolled from the United States Nationwide Readmission Database. MI and VTE readmissions were assessed at 30 and 180 days, and risks of a first thrombotic event were compared to that during a 30-day period before admission. Patients with asthma or cellulitis were used as controls.

At the 30-day assessment, 0.56 percent of discharged patients were readmitted with MI, while 0.76 percent were readmitted with VTE. By 180 days, 1.46 percent and 1.65 percent were readmitted with the respective conditions.

Relative to comparators initially admitted for asthma, participants who had been discharged for respiratory infections were nearly 50-percent more likely to be readmitted for MI (adjusted hazard ratio [HR], 1.48, 95 percent confidence interval [CI], 1.42–1.54), and saw an almost 30-percent greater likelihood of readmission for VTE (adjusted HR, 1.28, 95 percent CI, 1.24–1.33). Estimates relative to cellulitis controls were likewise statistically significant.

In the crossover-cohort analysis, thrombotic events also occurred more frequently after discharge than in the 30-day period before first admission for respiratory infection. For MI, there were 34 events per 10,000 discharges before the infection, which jumped to 57 events per 10,000 discharges after (odds ratio [OR], 1.68, 95 percent CI 1.62–1.73). For VTE, 24 events spiked to 79 events per 10,000 discharges after first admission (OR, 3.30, 95 percent CI, 3.19–3.41).