Typical patients?
Dedicated discussant Sana Al-Khatib, MD, MHS, Duke University Medical Center, Durham, N.C., said CRAVE is a “well-conducted and informative trial” that very nicely and effectively used a digital health platform.
She pointed out, however, that the trial enrolled healthy volunteers who not only owned a smartphone but were able to interact with the study team using it. They also had an average age of 38 years, median body mass index of 24 kg/m2, and no prior arrhythmias or cardiovascular issues. “These are not representative of the average patient that we see in clinical practice.”
“The other thing to keep in mind is that the primary outcome that they looked at, while relevant, is not adequate in my view to help us derive definitive conclusions about how coffee consumption affects clinically meaningful arrhythmias,” Dr. Al-Khatib said. “Yes, PACs trigger atrial fibrillation, but they don’t do so in every patient. And PVCs have been shown to be associated with increased mortality as well as worsened cardiovascular outcomes, but that’s mostly in patients with structural heart disease.”
She praised the investigators for including genetic data in their analysis. “Whether the results related to physical activity and sleep translate into any major effect on clinical outcomes deserves a study.”
The overall findings need to be replicated by other groups, in other populations, and examine hard outcomes over longer follow-up, concluded Dr. Al-Khatib.
Speaking to this news organization, Dr. Marcus countered that the participants were “pretty run of the mill” coffee drinkers of all ages and that the study highlights the complexity of coffee consumption as well as providing unique data inferring causality regarding increasing physical activity.
“Because coffee is so commonly consumed, highlighting the actual effects is important, and the hope is that understanding those true causal effects and minimizing confounding will help tailor recommendations regarding coffee consumption,” he said. “For those concerned about atrial fibrillation, for example, these data suggest that avoiding coffee does not necessarily make sense to reduce the risk of atrial fibrillation. For those with ventricular arrhythmias, abstinence or minimizing coffee may be a worthwhile experiment.”
Kalyanam Shivkumar, MD, PhD, director of the cardiac arrhythmia center at the University of California, Los Angeles, told this news organization that CRAVE is an important and much-needed study that provides reassuring and objective data for a common clinical question.
“It fits in with the emerging consensus that, in itself, coffee is not problematic,” he said. “And it provides a nice framework for what we’ll be seeing in the future – more studies that use these types of long ECG recordings and interlinking that data with biological readouts.”
Although it is too early to draw any conclusions regarding the genetic analyses, “future studies could use this as a baseline to further explore what happens between fast and slow metabolizers. This is a very useful stepping stone to putting data in context for an individual patient.”
Unless coffee consumption is excessive, such as over five cups per day in young people, all of the evidence points to coffee and caffeine being safe, Chip Lavie, MD, a frequent coffee researcher and medical director of cardiac rehabilitation and prevention at John Ochsner Heart and Vascular Institute, New Orleans, told this news organization.
“The benefits of coffee on physical activity/sleep seem to outweigh the risks as this current study suggests,” he said. “This study also supports the safety with regards to atrial arrhythmias, and suggests that those with symptomatic PVCs could try reducing coffee to see if they feel better. In total, however, the benefits of one or several cups of coffee per day on cardiovascular disease outweigh the risks.”
The study was funded by the University of California, San Francisco. Dr. Marcus reports research with the National Institutes of Health, the Patient-Centered Outcomes Research Institute, Tobacco-Related Disease Research Program, Medtronic, Eight Sleep, and Baylis; consulting for InCarda Therapeutics and Johnson & Johnson; and equity in InCarda Therapeutics as cofounder.
A version of this article first appeared on Medscape.com.