WATCH: The lead author of the study, Dr. Vicente Corrales-Medina, explains the findings.
TORONTO – If you’re hospitalized for pneumonia in old age, your chances of having a heart attack or stroke increase significantly, according to new Canadian research that suggests the sickness should be a risk factor for heart disease.
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Ottawa scientists say that doctors and elderly patients need to pay attention to cardiovascular health while battling pneumonia. Patients could encounter a heart attack while in hospital for pneumonia, and even weeks or months after their recovery.
“It’s not uncommon for patients to come in with acute pneumonia and a few days or weeks later, they come back with a heart attack. Our observation was that people with pneumonia, even when they survive the infection, have lower survival rates than people who don’t have pneumonia. Even with the same comorbidities, the same medical history,” Dr. Vicente Corrales-Medina, the study’s lead author, told Global News.
“The mechanisms for this association are still not well-characterized. We don’t understand why that happens,” he explained.
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Corrales-Medina is an infectious diseases expert at the Ottawa Hospital Research Institute and assistant professor at the University of Ottawa. The Peruvian native and U.S.-educated doctor had this “clinical observation” during his tenure.
“We thought it was more than a coincidence and wanted to look into it further,” he said.
Pneumonia is an infection in the lungs that causes inflammation in the air sacs. Its victims deal with symptoms such as cough, shortness of breath, fever and chills. In severe cases as the infection progresses, patients have impaired control over their vital functions – that’s when blood pressure could drop, for example.
It typically afflicts infants and seniors. The study, which Corrales-Medina conducted with University of Pittsburgh doctor Sachin Yende, zeroed in on adults, starting at age 45. The health records of about 3,800 U.S. patients were studied – 1,271 had pneumonia and 2,542 were control patients – both groups’ health data was studied for a decade.
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Pneumonia patients had a “raised level of risk” for heart disease over the entire 10 years – the highest risk was in the first year. For 65-year-olds and older, for example, a pneumonia patient was four times more likely to develop heart disease in the first 30 days following an infection. By their tenth year, they were about twice as likely next to their counterparts who hadn’t encountered pneumonia.
A 72-year-old woman with two heart disease risk factors – hypertension and smoking – increases her risk from 31 per cent to 90 per cent if she catches pneumonia, Corrales-Medina says.
Currently, there are only hypotheses to explain the ties between heart disease and pneumonia. In the short term, patients’ bodies are under high levels of stress. They could also have underlying cardiac conditions that trigger a heart attack.
“It may be that the heart can’t keep up with the demands. We suggest the cardiac reserve is not enough to meet demands imposed by the [pneumonia] and the heart can suffer, blood flow may already be impaired and then it faults in the stressful situation,” Corrales-Medina explained.
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But that doesn’t apply to long-term heart health issues. In that case, Corrales-Medina says the mechanisms are more complex: atherosclerosis, which is the hardening of the arteries, might be at play. Pneumonia sparks inflammation in the arteries, and could affect plaque levels in the artery walls over time.
His next steps in his research are to understand the biological mechanisms behind this raised heart disease risk post-pneumonia. That way, doctors can find interventions to stop the onset of heart disease.
For now, Corrales-Medina is hopeful his findings will encourage the elderly and medical communities do their best to prevent pneumonia in the first place. Vaccination and basic hand hygiene are their best bets.
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“This is especially important for the elderly and those with other risk factors for cardiovascular disease, such as diabetes, smoking and high cholesterol,” he said.
And if an elderly patient gets pneumonia, doctors can pay close attention to his or her heart health and develop a care plan with this information in mind.
Corrales-Medina’s full findings were published Tuesday morning in the Journal of the American Medical Association.