Friday, April 03, 2015

Bare metal versus drug eluting stents and hospital outcomes

The American Journal of Cardiology recently published these findings from a large database:

A total of 665,804 procedures were analyzed, which were representative of 3,277,884 procedures in the United States. Use of bare-metal stents (BMS) was associated with greater occurrence of in-hospital mortality compared with that of drug-eluting stents (DES; 1.4% vs 0.5%, p less than 0.001). The association stayed significant after adjustment of various possible confounding factors (odds ratio for DES versus BMS 0.59 [0.54 to 0.64, p less than 0.001]) and also in propensity matched cohorts (1.2% vs 0.7%, p less than 0.001). The results continued to be similar in the following high-risk subgroups: diabetes (0.57 [0.50 to 0.64, less than 0.001]), acute myocardial infarction and/or shock (0.53 [0.49 to 0.57, less than 0.001]), age greater than 80 (0.66 [0.58 to 0.74, less than 0.001]), and multivessel PCI (0.55 [0.46 to 0.66, less than 0.001]). In conclusion, DES use was associated with lesser in-hospital mortality compared with BMS. This outcome benefit was seen across subgroups in various subgroups including elderly, diabetics, and acute myocardial infarction as well as multivessel interventions.

This study suffers from the weakness of using an administrative database but was very large. Though it was previously known that the use of DES was associated with less lumen loss and restenosis over weeks it is not intuitive that it would reduce immediate term mortality. The authors do not offer a mechanism.

Early criticism of DES concerned costs compared with BMS, with hospitals under prospective payment wondering if they could afford to offer them. In this database the cost excess of DES, though statistically significant, was minimal and would be of questionable impact.

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