Improvement of silent myocardial ischaemia and reduction of plasma fibrinogen during nisoldipine therapy in occult coronary arterial disease.

The effect of the long-acting calcium channel blocking agent, nisoldipine, on silent myocardial ischaemia due to occult atherosclerotic coronary arterial disease has been evaluated in 12 asymptomatic patients (seven diabetics and five claudicants), none of whom had any history suggestive of ischaemic chest pain or previous myocardial infarction. All patients had normal resting electrocardiograms but positive exercise testing using 16-lead electrocardiographic mapping of the chest wall. They also had silent episodes of ST-segment depression during 24-hour ambulatory (Holter) monitoring. The study was of double-blind, cross-over design with four weeks randomised nisoldipine 10 mg twice daily versus placebo twice daily. Both the exercise test and Holter monitoring were carried out before entry to the trial and at the end of each randomised active and placebo phase. Plasma fibrinogen was also estimated at entry to the trial and at the end of each randomised phase. There were significant reductions in the magnitude (P less than 0.001) and duration (P less than 0.001) of depression of the ST segment on exercise testing and in the number of episodes (P less than 0.01), magnitude (P less than 0.001) and duration (P less than 0.02) of ST-segment depression on Holter monitoring at the end of the nisoldipine phase as compared to the randomised placebo phase. A significant reduction in plasma fibrinogen was also noted at the end of the nisoldipine phase (P less than 0.001). This study demonstrates the efficacy and usefulness of nisoldipine in treating myocardial ischaemia due to occult coronary arterial disease in asymptomatic subjects presenting with diabetes mellitus or intermittent claudication. Its use was associated with reduction in plasma fibrinogen.