As the data on worldwide deaths are starting to come in, our health prior to infection is the most important predictor of survival. In fact, the number one comorbidity in over 10% of deaths has been heart disease.
Here’s why. When we are infected with anything, our body has an increased metabolic demand to fight the infection. That means the body will ask the heart to do more. In the case of coronavirus, a lot more. The metabolic demands when we are infected with this sort of virus are typically four to eight times more than the normal workload on the heart. It’s kind of like running upstairs fast.
There is consensus among experts that both coronary artery disease and heart failure patients are at increased risk of acute events or exacerbations from viral respiratory infections, with other comorbidities (diabetes, obesity, hypertension, COPD, kidney disease) further increasing risk.
Acute viral infections have three categories of short-term effects on the cardiovascular system:
- increased risk of acute coronary syndromes associated with the severe inflammatory response to the infection
- myocardial depression leading to heart failure
- under-recognised risk of arrhythmias, also related to acute inflammation
It’s been suggested that influenza may precipitate plaque rupture, increase cytokines that destabilise plaques and trigger the coagulation cascade, but clear causal mechanisms by which flu precipitates adverse events are unclear. Studies in mice showed that influenza virus directly infects atherosclerotic plaques and causes severe cellular inflammation at vascular levels. There is also solid evidence that influenza infection can increase the risk of acute coronary syndromes and several trials have shown that influenza vaccination can prevent myocardial infarctions.
The American Heart Association (AHA) secondary prevention guidelines recommend influenza vaccination as a measure to reduce risk of cardiovascular events.
COVID-19 implications for patients with underlying cardiovascular conditions:
- Make plans for quickly identifying and isolating cardiovascular patients with COVID 19 symptoms from other patients, including in the ambulatory setting.
- Patients with underlying cardiovascular disease are at higher risk of contracting COVID 19 and have a worse prognosis.
- It is reasonable to advise all cardiovascular patients of the potential increased risk and to encourage additional, reasonable precautions.
- It is important for patients with CVD to remain current with vaccinations, including the pneumococcal vaccine given the increased risk of secondary bacterial infection with COVID 19.
- CVD patients should be vaccinated against influenza in accordance with current AHA guidelines.
- in geographies with active COVID 19 outbreaks, it may be reasonable to substitute telephonic or telehealth visits for in-person routine visits for stable CVD patients to avoid possible COVID 19 infection.
- It is reasonable to triage COVID 19 patients according to underlying cardiovascular, diabetic, respiratory, renal, oncological, or other comorbid conditions for prioritised treatment.
- Published case reports indicate patients with underlying comorbid conditions have a heighted risk for contracting COVID 19 and a worse prognosis.
- Case fatality rates for comorbid patients are materially higher than in the average population:
chronic respiratory disease: 6.3%
cardiovascular disease: 10.5%