Cardio Round-up: Walnuts Lower Blood Pressure, Arsenic Breaks the Heart, and More

This week’s edition of the Cardio Round-up highlights the perils for the heart of arsenic-contaminated drinking water, the blood pressure-lowering powers of walnuts, a caution about grapefruit, some post-hoc analysis of COMMANDER-HF, and a concerning trend of rising heart failure mortality in young adults.

Surprising nobody, arsenic in drinking water is associated with poor health outcomes, and this study highlighted the specific way in which arsenic exposure from contaminated drinking water leads to the thickening of heart muscle. The 1,337-participant study drew on patients from the Strong Heart Family Study. Measuring the sum of inorganic and methylated arsenic concentrations, the researchers reported associations between increased arsenic exposure and left ventricular hypertrophy, as well as other measures of ventricular dysfunction.

Grapefruits, often thought of as part of a nutritious breakfast, may have an unintended interaction with some drugs for treating long QT syndrome, according to a new Heart Rhythm paper. The study found that grapefruit consumption cause a delay in QT interval in health participants, and the delay was more significant and prolonged in female patients and those with long QT-syndrome. “[The] results of the present study would probably lead the FDA to call for additional studies before issuing a final recommendation based on its expected benefits and risks,” lead author Sami Viskin, MD, commented.

In what is a concerning trend, the rates of cardiovascular disease and heart failure are on the rise, particularly among adults in the 34 to 65 age range. Age-adjusted heart failure-related cardiovascular disease declined between 1999 and 2012, but the trends shifted, and an increase in mortality was noted in 2017. While a noticeable increase in younger adults over all was reported, the researchers also noted that black men and women incurred higher mortality burden than whites.

People who go nuts for walnuts (and who consume a diet low in saturated fats) should be pleased with a new study that highlighted walnuts in particular as being associated with improvements in some measures of high blood pressure. “It seems like there’s a little something extra in walnuts that are beneficial –maybe their bioactive compounds, maybe the fiber, maybe something else–that you don’t get in the fatty acids alone,” remarked Penny Kris-Etherton, PhD, RD, of the study results.

Rivaroxaban, when added to background antiplatelet therapy, was reported in a recent paper to also help lower the risk for thromboembolic events. This post-hoc analysis looked at the results from the COMMANDER-HF clinical trial. The analysis looked at patients who were given rivaroxaban versus placebo in the trial, and what effects on thromboembolic events could be observed. Fewer patients taking rivaroxaban had embolic events (including sudden and unwitness deaths). “The findings are not unexpected, since the rates of the parent trial’s primary end point components of MI and stroke were numerically reduced by rivaroxaban,” Marvin Konstam, MD, wrote in an editorial accompanying the study.