Nicorandil protects older patients from myocardial injury after PCI
Intravenous nicorandil cut the risk of periprocedural myocardial injury (pMI) after percutaneous coronary intervention (PCI) by 49 percent among patients 65 and older, according to a substudy of a randomized trial published in PLOS One.
The initial trial showed a nonsignificant decline in biomarker release and pMI among patients who received nicorandil or remote ischemic preconditioning (RIPC) when compared to a control group. However, lead author Norifumi Kawakita and colleagues predicted they could show a more significant impact of the interventions among older patients.
They then conducted another analysis of 282 patients 65 and older with stable coronary artery disease who were divided into three equal groups: RIPC, normal treatment (control) and IV nicorandil. Individuals in the nicorandil group received four mg of the drug at least one hour before PCI followed by continuous infusion of the vasodilatory drug (six mg/hour) for at least eight hours. The RIPC patients had a blood pressure cuff attached to their upper arm and received three rounds of inflation to 200 millimeters of mercury followed by deflation to 0 mm Hg—also performed at least one hour before PCI.
Rates of pMI were 37.2 percent for nicorandil, 43.0 percent for RIPC and 53.7 percent for the control group. The relative risk reductions for nicorandil and RIPC were 49 and 37 percent, respectively, when compared to the control group—although only nicorandil reached a statistically significant difference.
Kawakita et al. speculated that age-specific factors made nicorandil more useful in older patients versus those younger than 65. The drug is available in many European and Asian countries but not the United States.
“In patients with advanced age, microvascular function is considered to be impaired,” they wrote. “Nicorandil is a unique hybrid pharmacological agent of an adenosine triphosphate-sensitive potassium channel opener and nicotinamide nitrate. Therefore, an explanation for the beneficial effect of nicorandil is that nicorandil might compensate for a decline in cardiac mitochondrial function and ability of nitric oxide production in older patients.”
The authors said a small sample size may have hindered the ability to detect statistical significance in the evaluation of RIPC versus the control group. They suggested another multicenter, prospective study to further outline the effect of nicorandil on pMI in older patients.