Heart medication study shows growing power of outcome studies

The recent advisory from the Society for Cardiovascular Angiography and Interventions to health care providers to avoid prescribing proton pump inhibitor drugs in dual-platelet therapy for patients who have received stents, besides sending a shockwave to PPI makers, demonstrates the growing power of outcomes studies—especially large-sample ones.

The study, involving nearly 17,000 patients, shows that PPIs pantoprazole (Protonix), esomeprazole (Nexium), omeprazole (Prilosec), and Lansoprazole (Prevacid), when used in combination with Plavix (clopidogrel), raise the risk of heart attack and stroke for patients recovering from stent placement surgery. The society asked healthcare providers to “consider prescribing a histaminergic (H2) blocker (such as Zantac or Tagamet) or antacids instead of a PPI, considering the high risk for adverse events shown in this study,” according to an announcement.

The study was conducted by Medco Health Solutions Inc. (Franklin Lakes, NJ) and the Indiana University School of Medicine (Indianapolis). Researchers found that using any one of the PPIs in conjunction with Plavix increases the risk of hospitalization for a cardiovascular event by 51%. While acknowledging that still more research is needed, the society notes that the study is the largest trial to date to examine the outcomes of patients who are taking Plavix and a PPI.

While there is no question that the results are significant for heart patients and cardiologists, the study is also notable for putting a spotlight on what Medco calls its Therapeutic Resource Centers, which develop clinical evidence based on tracking patient prescription and treatment records. Within this, Medco and Indiana U. have set up a program called the Clopidogrel Outcomes Study; the PPI report is one of a series from that program. Such outcomes studies will set a pattern for comparative effectiveness research (CER), which is now getting greatly expanded funding in the Obama Administration.

Plavix is one of the world’s most prescribed drugs, according to the announcement, and ranked third in 2008 US pharmaceutical sales. “While this study confirms prior research, it brings us a step further in our understanding by showing that this is a problem associated with each of the four most popular PPIs,” says Dr. Robert Epstein, chief medical officer at Medco and one of the study researchers, in the announcement.