Bacterial Pneumonia Linked to Increased Risk of Acute Cardiac Events

HOUSTON, June 19 -- Myocardial infarction and other acute cardiac events closely track pneumococcal pneumonia, which suggests a need for multiple admitting diagnoses.
A review of medical records from 170 patients admitted to a hospital here for pneumococcal pneumonia revealed that one in five patients had at least one concurrent major cardiac event, said Daniel M. Musher, M.D., of the Veterans Affairs Medical Center here, and colleagues.
Moreover, patients who had concurrent pneumococcal pneumonia and cardiac events had significantly higher mortality (P <0.008), they reported in the July 15 issue of Clinical Infectious Diseases.
Dr. Musher said increased cardiac stress, hypoxemia, and inflammation all contribute to the increased risk of cardiac events among patients with acute bacterial pneumonia.
He and his colleagues studied records of patients admitted from 2001 through 2005.
Among the findings:
Thirty-three patients (19.4%) had one or more acute cardiac events.
Twelve patients had MIs, eight had new-onset arrhythmia or recurrent arrhythmia without MI, and 13 had new-onset or worsening congestive heart failure without MI.
Atrial fibrillation was the most common serious arrhythmia, occurring in seven of eight patients with new onset arrhythmia.
Among patients who had cardiac events 69% were hypoxic at admission, and 46% had hemoglobin levels of ≤ 10 gm/dL.
Four of the 13 congestive heart failure patients died during the hospitalization.
"The concurrence of pneumonia and a new cardiac event was often unrecognized, especially in the first 12 to 24 [hours] of hospitalization, resulting in some patients not receiving cardiac monitoring or anticoagulant therapy," they wrote.
The study was limited by its uncontrolled design, which failed to account for other comorbidities that could adversely affect oxygen demand. Moreover the patients were all older veterans "with a high prevalence of tobacco abuse, and thus may have had a higher likelihood of underlying coronary artery disease."
In conclusion, the authors cautioned that the practice of using a unifying diagnosis may "lead initially to consideration of one, rather than both conditions." They suggest using multiple admitting diagnoses to avoid that potential problem.
The study was funded by a Veterans Affairs Merit Review Grant and by a National Institutes of Health Training Grant. Dr. Musher reported no conflicts. Primary source: Clinical Infectious DiseasesSource reference: Musher DM et al "The Association between Pneumococcal Pneumonia and Acute Cardiac Events" CID 2007:45 (15 July) 000