- Jennifer Middleton, MD, MPH
Updates on diagnosis, treatment, and prevention of cardiovascular disease (CVD) abounded in the medical literature over the last month. While these studies' findings were largely non-significant or limited, they still provide clarity regarding current best practices while paving the way for future research.
First, the search for a clinical decision rule to stratify patients presenting to primary care with chest pain regarding risk of acute coronary syndrome (ACS) will have to continue, as the results of a "flash mob" study, published this month in the Annals of Family Medicine, failed to validate the Marburg Heart Score for use in primary care. The investigators recruited nearly 20% of the family physicians in the Netherlands to gather data on patients with suspected ACS during a 2 week time period. The family physicians sent information back to the investigators using a brief case report form, filed either electronically or on paper. Although the study results were disappointing, the feasibility of this novel research method was more promising. Perhaps we'll see more "flash mob" studies in the near future.
In an AFP Medicine By the Numbers summary out today, a Cochrane review of early reperfusion therapy in patients with STEMI received a "no benefits" rating by the thennt.com. The meta-analysis examined data from 8 randomized controlled trials including a total of over 8900 participants, all with chest pain at rest and either EKG changes consistent with STEMI (ST-segment myocardial infarction), NSTEMI (non-ST-segment myocardial infarction), or a previously established diagnosis of coronary artery disease. Participants were randomized to either receive reperfusion immediately or to receive medical therapy first with reperfusion only if symptoms persisted. There was no mortality benefit to early reperfusion, and participants who underwent early reperfusion were also more likely to have a periprocedural myocardial infarction (MI) or a major bleeding event. The risk of these adverse events was deemed to outweigh the found benefits of increased relief from refractory chest pain, decreased repeat hospitalization, and decreased risk of a susbsequent MI in the next year with early reperfusion.
Finally, an umbrella review (a systematic review of prior meta-analyses) sought to identify the best current evidence regarding diet changes and supplements on improving CVD outcomes. These investigators found moderate quality evidence to support reduced salt intake (lower all-cause mortality in individuals without hypertension, and lower cardiovascular mortality in individuals with hypertension). Lower quality evidence correlated omega-3-fatty-acid intake with lower risks for MI and CAD. Folic acid intake correlated with lower stroke risk, though the authors caution that this finding was largely driven by a study based in China, where fewer foods are fortified with folate than in the United States. Interestingly, calcium and vitamin D intake correlated with a higher stroke risk. "Other nutritional supplements, such as vitamin B6,
vitamin A, multivitamins, antioxidants, and iron and dietary inter-
ventions, such as reduced fat intake, had no significant effect on
mortality or cardiovascular disease outcomes (very low– to
moderate-certainty evidence)." Given the relative low quality of many studies, the authors' call for further, more rigorous research is understandable.
Studies finding a lack of benefit (the Marburg score "flash mob" and the early reperfusion meta-analysis) are still useful to help family physicians avoid harm and to spur the search for better alternatives. Hopefully, more rigorous research will come to verify the findings of the nutrition and supplement umbrella review. We'll look forward to reporting on these hoped-for follow-up studies; in the meantime, what research would you like see to regarding CVD in primary care?