Pneumonia hospitalization may increase risk of cardiovascular disease

More data from the Cardiovascular Health Study (CHS) and Atherosclerosis Risk in Communities Study (ARIC): Pneumonia may increase the risk for cardiovascular disease development both in the short and long term.

According to findings published Jan. 20 in JAMA, researchers taking a second look at the community-based studies found that patients who were hospitalized for pneumonia later had higher rates of MI, stroke and fatal coronary heart disease events. In general, these patients had higher mortality rates than patients who did not contract pneumonia.

CHS and ARIC were studied separately but concurrently by Vicente F. Corrales-Medina, MD, MSc, from the University of Ottawa and the Ottawa Hospital Research Institute, and colleagues. Differences in baseline clinical characteristics and risks encouraged researchers to maintain the two as separate cohorts. Pneumonia-hospitalized patients from each study were paired with similar patients without pneumonia during that period. Patients included in this review did not previously have cardiovascular disease.

Corrales-Medina et al found that between those with documented hospitalization for pneumonia and those without, in the ARIC study there was a twofold increased risk and in the CHS study a fourfold increased risk at 30 days for a cardiovascular event. Risk remained high through one year in both pneumonia groups (hazard ratio 2.19 and 2.10, respectively), and remained significant beyond one year (second year CHS hazard ratio 1.89, ARIC 1.88). This is considerably higher than adjusted hazard ratios for smoking (1.18) and diabetes (1.19), and were comparable with hypertension (1.84).

In CHS patients hospitalized for pneumonia, mortality was 18.8 percent at 30 days, 24.7 percent at 90 days, 35.9 at one year, 58.9 percent at five years and 70.9 percent at 10 years. Mortality for pneumonia patients in ARIC represented 11.8 percent at 30 days, 15.7 percent at 90 days, 24.7 percent at one year, 44.1 percent at five years and 76.2 percent at 10 years.

Of the CHS patients with pneumonia, 34.8 percent had cardiovascular events over the intervening 10-year span: MI comprised 50.5 percent of events; stroke, 17 percent, and fatal coronary heart disease events, 32.5 percent. In the 10-year span, 16.5 percent of ARIC patients had cardiovascular events: 29.5 percent with MI, 32.1 percent with stroke and 38.4 percent had fatal coronary heart disease.

Corrales-Medina et al suggested that the high risks seen in these patients may relate to increased inflammatory markers noted in patients hospitalized for pneumonia, in spite of recovery from the initial illness. They suggested that in the future, pneumonia hospitalization be considered when assessing cardiovascular disease risks.