Bacterial pneumonia tied to higher MACE risk than viral pneumonia
Individuals hospitalized with pneumonia have an elevated risk of developing major adverse cardiovascular events (MACE), with a greater risk among those with bacterial compared with viral pneumonia, according to a recent study presented at AHA 2018.
The study involved 4,792 adult patients who were hospitalized at any of the 23 hospitals under the Intermountain Healthcare System in Utah, US, for acute pneumonia between January 2007 and May 2014.
Seventy-eight percent of patients (n=3,736) were diagnosed with bacterial pneumonia based on either positive culture (n=756; Streptococcus pneumoniae the causative bacteria in 91 percent of these cases) or primary diagnosis code for bacterial pneumonia (n=2,980). Twenty-one percent of patients (n=993) were diagnosed with viral pneumonia, 40 percent of whom had influenza (n=397), with the remaining 1 percent of patients having both bacterial and viral pneumonia.
About one-third of patients experienced MACE (n=1,531) within 90 days of hospitalization, which included heart failure (n=1,192), stroke (n=37), myocardial infarction (MI; n=18), and all-cause mortality (n=547).
The risk of 90-day MACE was 60 percent higher among patients with bacterial compared with viral pneumonia (34 percent vs 26 percent, adjusted odds ratio, 1.6, 95 percent confidence interval, 1.27–2.02; p=0.002). [AHA 2018, abstract Su1070/1070]
Compared with patients who did not experience MACE in 90 days, those who did were older (mean, 72 vs 59 years; p<0.0001), had a prior history of MI (10 percent vs 3 percent; p=0.04), heart failure (78 percent vs 9 percent; p<0.0001), dysrhythmia (65 percent vs 31 percent; p=0.002), or renal failure (52 percent vs 31 percent; p=0.003), or had history of corticosteroid (53 percent vs 36 percent; p<0.0001) or beta blocker use (49 percent vs 22 percent; p<0.0001).
“The likely underlying cause is that bacterial pneumonia causes greater inflammation of the arteries compared [with] viral pneumonia,” said Dr J. Brent Muhlestein, a cardiovascular researcher with the Intermountain Heart Institute at Intermountain Medical Center, Salt Lake City, Utah, US.
“We’ve always known pneumonia was a risk factor for a major adverse cardiac event, like a heart attack, within the first 90 days of being diagnosed … what we didn’t know was which type of pneumonia was more dangerous,” he said.
“The practical result of our study is that caregivers should be aware of the greater cardiovascular risks associated with respiratory infections like pneumonia, and especially bacterial pneumonia. If a patient has been diagnosed with bacterial pneumonia, treat it aggressively and watch them closely for any signs of a heart attack or stroke. If the patient is taking medications specific to a heart condition, like high blood pressure or cholesterol, they should continue taking those prescribed medications,” Muhlestein concluded.