Detection and Management of Geographic Disparities in the TOPCAT Trial: Lessons Learned and Derivative Recommendations.

TOPCAT was a multinational clinical trial of 3,445 heart failure with preserved ejection fraction (HFpEF) patients that enrolled in 233 sites in six countries in North America, Eastern Europe and South America. Patients with a heart failure hospitalization in the last 12 months or an elevated B-type natriuretic peptide (BNP) were randomized to the mineralocorticoid receptor antagonist spironolactone vs. placebo. Sites in Russia and the Republic of Georgia provided the majority of early enrollment, primarily based on the hospitalization criterion since BNP levels were initially unavailable there. With the emergence of country-specific aggregate event rate data indicating lower rates in Eastern Europe and differences in patient characteristics there, the DSMB recommended relatively increasing enrollment in North America plus other corrective measures. Although final enrollment reflected the increased contribution from North America, a plurality of the final cohort came from Russia and Georgia (49% vs. 43% in North America). BNP measurements from Russia and Georgia available later in the trial suggested no or a mild level of heart failure consistent with low event rates. The primary results showed no significant spironolactone treatment effect overall (primary endpoint hazard ratio 0.89 (0.77, 1.04)), with a significant hazard ratio in North and South America (0.82 (0.69, 0.98), p =0.026) but not in Russia and Georgia (1.10 (0.79, 1.51), interaction p = 0.12). This report describes the DSMB's detection and management recommendations for regional differences in patient characteristics in TOPCAT, and suggests methods of surveillance and corrective actions that may be useful for future trials.

Cost-effectiveness of percutaneous coronary intervention with drug eluting stents versus bypass surgery for patients with diabetes mellitus and multivessel coronary artery disease: results from the FREEDOM trial.

BACKGROUND: Studies from the balloon angioplasty and bare metal stent eras have demonstrated that coronary artery bypass grafting (CABG) is cost-effective compared with percutaneous coronary intervention (PCI) for patients undergoing multivessel coronary revascularization-particularly among patients with complex coronary artery disease or diabetes mellitus. Whether these results apply in the drug-eluting stent (DES) era is unknown. METHODS AND RESULTS: Between 2005 and 2010, 1900 patients with diabetes mellitus and multivessel coronary artery disease were randomized to PCI with DES (DES-PCI; n=953) or CABG (n=947). Costs were assessed from the perspective of the U.S. health care system. Health state utilities were assessed using the EuroQOL 5 dimension 3 level questionnaire. A patient-level microsimulation model based on U.S. life-tables and in-trial results was used to estimate lifetime cost-effectiveness. Although initial procedural costs were lower for CABG, total costs for the index hospitalization were $8622 higher per patient. Over the next 5 years, follow-up costs were higher with PCI, owing to more frequent repeat revascularization and higher outpatient medication costs. Nonetheless, cumulative 5-year costs remained $3641 higher per patient with CABG. Although there were only modest gains in survival with CABG during the trial period, when the in-trial results were extended to a lifetime horizon, CABG was projected to be economically attractive relative to DES-PCI, with substantial gains in both life expectancy and quality-adjusted life expectancy and incremental cost-effectiveness ratios <$10 000 per life-year or quality-adjusted life-year gained across a broad range of assumptions regarding the effect of CABG on post-trial survival and costs. CONCLUSIONS: Despite higher initial costs, CABG is a highly cost-effective revascularization strategy compared with DES-PCI for patients with diabetes mellitus and multivessel coronary artery disease. CLINICAL TRIAL REGISTRATION: URL: http://www.clinical-trials.gov. Unique identifier: NCT00086450.