The COVID-19 pandemic has caused a substantial decline in overall heart surgery volume in the USA, and can be linked to an unexplained increase in deaths after coronary artery bypass grafting (CABG), according to late-breaking research presented at the 57th Annual Meeting of The Society of Thoracic Surgeons (STS 2021, 29–31 January, virtual).
The research, presented by Tom Nguyen (University of California San Francisco, San Francisco, USA), analysed data from the STS Adult Cardiac Surgery Database from January 1, 2018, to June 30, 2020, and The Johns Hopkins COVID-19 Dashboard from February 1, 2020, to January 1, 2021.
Nguyen and colleagues examined data from 717,103 adult cardiac surgery patients and more than 20 million COVID-19 patients in an effort to determine how the pandemic affected adult cardiac surgery on national and regional levels.
According to the study results, there was a 53% decrease nationwide in all adult cardiac surgery volume when compared to 2019 and 65% fewer elective cases in the USA. COVID-19 also impacted non-elective cases, resulting in a 40% decrease.
In addition, the data showed that no matter the procedure—isolated CABG, isolated aortic valve replacement (AVR), isolated mitral valve replacement (MVR), CABG+AVR, CABG+MVR, isolated MV repair, and CABG+MV repair—there was a significant decline in case volume—54%—when compared to 2019.
“This study was a true herculean analysis and tour de force that showed the COVID effect on adult cardiac surgery volume, trends, and outcomes,” said Nguyen. “The pandemic has changed the world as we know it, causing a dramatic drop in adult cardiac surgery volume and worsening patient outcomes.”
“Only the STS National Database has the level of granularity, COVID variables, and longitudinal follow-up to answer the questions posed in this important study,” said Dr. Nguyen. “Our research also analysed data by regions to get an idea of how specific areas did during the COVID pandemic.”
Regionally, the Mid Atlantic area (New York, New Jersey, and Pennsylvania), was among those most affected by the COVID crisis, experiencing a 71% decrease in overall case volume, 75% fewer elective cases, and a 59% reduction in non-elective cases. Another hotspot, the New England region (Maine, Vermont, New Hampshire, Massachusetts, Connecticut and Rhode Island), showed a 63% reduction in overall case volume.
The researchers also found that prior to the COVID-19 surge, the Mid-Atlantic and New England regions had excellent outcomes with an observed-to-expected (O/E) ratio of less than one, which represents a better-than-expected mortality rate. However, during the COVID-19 surge, there was a 110% increase in the O/E for all adult cardiac procedures and a 167% increase for isolated CABG, meaning more patients were dying than expected.
Though the data did not directly address the cause of increased mortality, many surgeons say they currently are limited to operating on only the most urgent coronary bypass cases and patients who tend to be sicker. “These numbers should not serve as a deterrent to patients seeking care for chest pain or other cardiac symptoms,” said Robbin G Cohen from Keck School of Medicine of the University of Southern California, Los Angeles, USA, who was not directly involved with this study. “If anything, they are a warning to get into the system as soon as possible.”
According to Nguyen, this study is only the first of many more “granular” analyses to come. The researchers plan to examine trends and outcomes of COVID-19 patients versus non-COVID-19 patients, as well as delve more into the COVID-19 effect on specific adult cardiac procedures such as aortic dissections.