Nicorandil improves myocardial high-energy phosphates in postinfarction porcine hearts

Nicorandil decreases cardiac events during and after noncardiac surgery

STUDY OBJECTIVE

To assess whether nicorandil reduces the likelihood of cardiac events during and after intermediate risk surgery.

DESIGN

Multicenter study.

SETTING

13 hospitals in Japan.

PATIENTS

Intermediate-risk patients were identified by the presence of risk factors such as angina, a history of myocardial infarction, heart failure, diabetes mellitus, and abnormal electrocardiography (ECG).

INTERVENTIONS

Nicorandil was given to these patients during the operation.

MEASUREMENTS AND MAIN RESULTS

Cardiac events during the operation and the following 5 days were monitored. The frequency of cardiac events in nicorandil-treated patients was compared with those in nontreated patients. Eighty-four patients received nicorandil during surgery and 237 patients received standard care. Cardiac events in the nicorandil-treated group occurred less frequently both during the operation (odds ratio, 0.15; 95% confidence interval, 0.03-0.76; P=0.02) and after it (odds ratio, 0.24; 95% confidence interval, 0.06-0.90; P=0.04).

CONCLUSIONS

Nicorandil reduces the frequency of cardiac events in patients undergoing noncardiac surgery, both during and after the operation.

Effects of pravastatin on ventricular remodeling by activation of myocardial KATP channels in infarcted rats: role of 70-kDa S6 kinase

Reactive cardiomyocyte hypertrophy after myocardial infarction is an important risk factor for arrhythmias. Myocardial ATP-sensitive potassium (K(ATP)) channels have been implicated in attenuating cardiac hypertrophy by inhibition of 70-kDa S6 kinase. We investigated the effect of pravastatin on ventricular hypertrophy during remodeling after myocardial infarction and whether the attenuated hypertrophic effect was via activation of myocardial K(ATP) channels. Twenty-four hours after ligation of the anterior descending artery, male Wistar rats were randomized to either vehicle, nicorandil (an agonist of K(ATP) channels), pravastatin, glibenclamide (an antagonist of K(ATP) channels), or a combination of nicorandil and glibenclamide or pravastatin and glibenclamide for 4 weeks. Infarct size and mortality were similar among the infarcted groups. Cardiomyocyte sizes isolated by enzymatic dissociation after infarction significantly increased at the border zone in vehicle-treated infarcted rats compared with sham-operated rats. Rats in the nicorandil- and pravastatin-treated groups significantly attenuated cardiomyocyte hypertrophy, as compared with the vehicle-treated group. Arrhythmic scores during programmed stimulation mirrored those of cardiomyocyte hypertrophy. Increased 70-kDa S6 kinase mRNA expression in cardiac remodeling was confirmed by reverse transcription-polymerase chain reaction, consistent with the results of immunohistochemistry and Western blot for the phosphorylation of 70-kDa S6 kinase. Nicorandil-induced effects were abolished by administering glibenclamide. Similarly, the beneficial effects of pravastatin were abolished by administering glibenclamide, implicating K(ATP) channels as the relevant target. Activation of K(ATP) channels by pravastatin administration can attenuate ventricular remodeling through a S6 kinase-dependent pathway after infarction.