According to recent reports on the coronavirus outbreak in the United States, an increase in mortality during the pandemic cannot be explained by Covid-19 deaths alone.

In a new study from the Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology at Beth Israel Deaconess Medical Center (BIDMC), researchers analysed data from the National Center for Health Statistics to compare the rate of cardiovascular-related deaths before and after the onset of the pandemic. This was compared to the same periods in the prior year.

The study, published in the Journal of the American College of Cardiology (JACC), found that cardiovascular deaths unrelated to Covid-19 increased during the pandemic.

Study author, Rishi K Wadhera, a cardiologist and researcher at the Smith Center and BIDMC said: “Hospital visits for heart attacks and other cardiac conditions declined markedly during the pandemic, fuelling physicians’ concerns that people with acute conditions may be staying at home due to fear of exposure to COVID-19.”

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“Our research raises concern that the avoidance of hospitals, deferral of semi-elective procedures and care, and substantial strain imposed on hospitals during the early phase of the pandemic may have had an indirect toll on patients with cardiovascular disease,” he added.

Wadhera and the team evaluated the rate of US deaths due to cardiovascular causes after the onset of the Covid-19 pandemic (mid-March to June 2020) relative to the immediately preceding 11 weeks pre-pandemic. The team also compared these two periods of 2020 to the same weeks in 2019.

The team found a significant rise in cardiac deaths after the onset of the pandemic in the US. Deaths due to ischemic heart diseases (related to narrowing of the arteries) and hypertensive (related to high blood pressure) diseases increased by 11 per cent and 17 per cent, respectively, compared to the previous year.

New York City witnessed the largest relative rise in deaths (139 per cent) due to ischemic heart diseases.

“These data are particularly relevant today, as we find ourselves in the midst of a surge in Covid-19 cases that looks to be exceeding what we experienced last spring,” said senior author Robert Yeh, Director of the Smith Center for Outcomes Research at BIDMC.

He added: “Ensuring that patients with the cardiovascular disease continue to receive necessary care during our public health response to the pandemic will be of paramount importance.”

The authors of the study suggested that the strain imposed by Covid-19 on some hospitals may have also led to delays in care for hospitalised patients without Covid-19. The pandemic-related deferral of semi-elective procedures, as well as delays in emergency service response times, have also contributed to a spike in the death rate.

“Overall, our data highlight the urgent need to improve public health messaging and rapidly expand health care system resources to ensure that patients with emergent conditions seek and receive medical care -- particularly in regions currently experiencing a sharp rise in Covid-19 cases,” Wadhera said.