Latest medical research sheds light on mask mandates, cardiovascular disease

There are countless medical journals and research studies that are relevant to DOs and the work they do. Keeping up with the latest medical research is an important part of a career in medicine, but it can be challenging to follow so many different resources. We searched through the latest research to find four new studies that many DOs will find significant. See below for summaries and links to the original research.

“Evaluating the effectiveness of countywide mask mandates at reducing SARS-CoV-2 infection in the United States,” Journal of Osteopathic Medicine, April 2022

During the rise of the Delta variant of COVID-19, this study compared U.S. counties with and without mask mandates and determined if the mandates were related to a decrease in daily COVID-19 infection. A total of 38 counties were studied, each with populations between 40,000 and 105,000. These counties were all located within randomly selected states that did not have statewide mask mandates. Test counties were followed for 30 days after mask mandates were implemented; daily COVID-19 infection rates were recorded during this 30-day timeframe.

The data collected showed that counties that passed mask mandates had significantly lower averages of daily COVID-19 infection than in counties that did not have mask mandates. The difference-in-difference analysis revealed a 16.9% reduction in predicted COVID-19 cases at the end of the 30-day timeframe. The data supports the effectiveness of mask mandates to reduce the infection rate of COVID-19 in small U.S. counties.

“Aspirin Use to Prevent Cardiovascular Disease,” The Journal of the American Medical Association, April 2022

Cardiovascular disease (CVD) is the leading cause of death in the United States; it accounts for more than 1 in 4 deaths. Each year, an estimated 605,000 Americans have a first myocardial infarction, while an estimated 610,000 have a first stroke. This research by the U.S. Preventive Services Task Force (USPSTF) aimed to review the effectiveness of aspirin to reduce the risk of CVD events, cardiovascular mortality and all-cause mortality in people without a history of CVD. The research also investigated the effects of aspirin use for colorectal cancer, in addition to the potential risks, such as bleeding, associated with aspirin use.

The review examined adults 40 years or older who had no signs or symptoms of CVD or known CVD, including history of myocardial infarction or stroke, and who were not at increased risk for bleeding. The data concludes with “moderate certainty” that using aspirin for the primary prevention of CVD events in adults aged 40 to 59 years old has a small net benefit. Additionally, the researchers conclude, again with “moderate certainty,” that aspirin use to prevent CVD events in adults 60 years or older has no net benefit. The USPFTF says that adults 40 to 59 years old who have a 10% or greater 10-year CVD risk can consider using low-dose aspirin.

“Effects of Medical Face Masks on Physical Performance in Patients With Coronary Artery Disease or Hypertension,” The American Journal of Cardiology, April 2022

This study was a randomized, prospective monocentric study in which 40 subjects with coronary artery disease or hypertension were assigned either a surgical mask or class 2 filtering facepiece. Each subject performed cycle ergometry exercise tests that progressively increased in intensity until the subjects reached the point of exhaustion. A test was performed with the masks/facepieces and without in random order. A control group of 10 health subjects randomly performed three exercise tests with the mask, facepiece and with no mask at all. Blood pressure, heart rate, 12-lead electrocardiogram, exertion, shortness of breath and capillary blood gases from the earlobe were all documented.

Across all groups, exercising while wearing the mask or facepiece significantly reduced peak power output in watts compared to exercising with no mask, without differences in hemodynamic parameters, such as maximum heart rate and systolic blood pressure. Those wearing the facepiece in comparison to those not wearing a mask resulted in a significantly higher carbon dioxide partial pressure with corresponding differences in hydrogen carbonate and base excess, but not to a clinically critical extent.

The study concludes that exercise testing with a mask or facepiece resulted in a significant reduction of peak power output without differences in hemodynamic parameters in subjects with pre-existing CVD and in healthy subjects.

“CT or Invasive Coronary Angiography in Stable Chest Pain,” The New England Journal of Medicine, April 2022

When it comes to diagnosing obstructive coronary artery disease (CAD), computed tomography (CT) is an accurate, noninvasive alternative to invasive coronary angiography (ICA). However, the effectiveness of CT vs. ICA in the management of CAD to reduce the frequency of major adverse cardiovascular events is unknown.

This study was a pragmatic, randomized trial comparing CT with ICA as initial diagnostic imaging strategies for guiding the treatment of patients with stable chest pain who had an immediate pretest probability of obstructive CAD and were referred for ICA at one of 26 European centers. Over 3.5 years, the primary outcome was major adverse cardiovascular events, i.e., cardiovascular death, nonfatal myocardial infarction or nonfatal stroke. Key secondary outcomes were procedure-related complications and angina pectoris.

The study included 3,561 patients, 56.2% of whom were women. Follow-up was complete for 3,523 patients, or 98.9%. Major adverse cardiovascular events occurred in 38 of 1,808 patients, or 2.1%, in the CT group and in 52 of 1,753, or 3.0%, in the ICA group. Major procedure-related complications occurred in 9 patients (0.5%) in the CT group and in 33 patients (1.9%) in the ICA group. Angina during the final 4 weeks of follow-up was reported in 8.8% of the patients in the CT group and in 7.5% of those in the ICA group.

The study concluded that the risk of major cardiovascular events was similar in the CT group and the ICA group. Additionally, the frequency of major procedure-related complications was lower with an initial CT strategy.