Cardiac Complications in Patients With Community-Acquired Pneumonia: Incidence, Timing, Risk Factors, and Association With Short-Term Mortality

Study Questions:

What are the type, frequency, and timing of incident cardiac complications; their risk factors; and associations with short-term mortality in patients with community-acquired pneumonia (CAP)?

Methods:

A total of 1,343 inpatients and 944 outpatients with CAP were followed up prospectively for 30 days after presentation. Incident cardiac complications (new or worsening heart failure, new or worsening arrhythmias, or myocardial infarction) were diagnosed in 358 inpatients (26.7%) and 20 outpatients (2.1%). For the univariable analysis of baseline factors and incident cardiac complications, the authors used unpaired t tests or Wilcoxon rank-sum tests for continuous variables and χ2 or Fisher exact tests for categorical variables, as appropriate. The authors also sought to explore its association with the risk of incident cardiac complications by using a multivariable model.

Results:

Although most events (89.1% in inpatients, 75% in outpatients) were diagnosed within the first week, more than half of them were recognized in the first 24 hours. Factors associated with their diagnosis included older age (odds ratio [OR],1.03; 95% confidence interval [CI], 1.02-1.04), nursing home residence (OR, 1.8; 95% CI, 1.2-2.9), history of heart failure (OR, 4.3; 95% CI, 3.0-6.3), prior cardiac arrhythmias (OR, 1.8; 95% CI, 1.2-2.7), previously diagnosed coronary artery disease (OR, 1.5; 95% CI, 1.04-2.0), arterial hypertension (OR, 1.5; 95% CI, 1.1-2.1), respiratory rate ≥30 breaths per minute (OR, 1.6; 95% CI, 1.1-2.3), blood pH <7.35 (OR, 3.2; 95% CI, 1.8-5.7), blood urea nitrogen ≥30 mg/dl (OR, 1.5; 95% CI, 1.1-2.2), serum sodium <130 mmol/L (OR, 1.8; 95% CI, 1.02-3.1), hematocrit <30% (OR, 2.0; 95% CI, 1.3-3.2), pleural effusion on presenting chest X-ray (OR, 1.6; 95% CI, 1.1-2.4), and inpatient care (OR, 4.8; 95% CI, 2.8-8.3). Incident cardiac complications were associated with increased risk of death at 30 days after adjustment for baseline Pneumonia Severity Index score (OR, 1.6; 95% CI, 1.04-2.5).

Conclusions:

The authors concluded that incident cardiac complications are common in patients with CAP and are associated with increased short-term mortality.

Perspective:

This study suggests that incident cardiac complications occur in a substantial proportion of patients with CAP, affecting more than one quarter of those hospitalized for this infection; that the great majority of CAP patients who develop incident cardiac complications have their primary cardiac event within 7 days of presentation, with >50% occurring the same day of CAP diagnosis; and the development of incident cardiac complications is independently associated with a 60% increase in the risk of short-term mortality in patients with CAP. The study findings provide support for increasing efforts to reduce the incidence of pneumonia in high-risk populations through influenza and pneumococcal vaccination.

Clinical Topics: Heart Failure and Cardiomyopathies, Prevention, Atherosclerotic Disease (CAD/PAD), Acute Heart Failure, Hypertension

Keywords: Risk, Coronary Artery Disease, Pneumonia, Pleural Effusion, Sodium, X-Rays, Statistics, Nonparametric, Respiratory Rate, Blood Urea Nitrogen, Risk Factors, Inpatients, Community-Acquired Infections, Hematocrit, Outpatients, Hydrogen-Ion Concentration, Confidence Intervals, Vaccination, Hypertension, Odds Ratio, Myocardial Infarction, Influenza, Human, Nursing Homes, Incidence, Heart Failure


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