Effect of spirapril and hydrochlorothiazide on platelet function and euglobulin clot lysis time in patients with mild hypertension.

Thirteen patients with mild hypertension (untreated diastolic blood pressure of 95 to 114 mmHg) received, in random order, three successive treatments of four weeks with placebo, spirapril (6 mg daily), or hydrochlorothiazide (HCT2) (24 mg daily). At the end of each treatment, blood samples for assessment of platelet aggregation and platelet release of platelet factor 4 (PF4) and for assessment of fibrinolysis, estimated by tissue plasminogen activator (t-PA), plasminogen activator inhibitor-type 1 (PAI-1), and euglobulin clot lysis time (ECLT), were taken, first at rest, then immediately after five to ten minutes of vigorous exercise, and finally after the subsequent hour of recovery rest. Platelet aggregation induced in vitro by adrenaline significantly decreased during treatment with HCT2, the threshold rising to 10 microM as compared with 1.

ACE inhibition with spirapril improves diastolic function at rest independent of vasodilation during treatment with spirapril in mild to moderate hypertension.

The effects of the ACE inhibitor spirapril and of hydrochlorothiazide on left ventricular diastolic function were studied. Thirteen patients with mild to moderate essential hypertension completed this randomized, double-blinded, placebo-controlled, crossover study. After a three-week run-in period the patients entered three periods lasting four weeks each, wherein they were treated with placebo, spirapril, or hydrochlorothiazide.

Smoking further increases platelet activity in patients with mild hypertension.

In this study the authors examine whether smoking further heightens platelet activity and reduces fibrinolysis above that already present in mild hypertension. Ten smokers and 11 non-smokers, all with mild hypertension (defined as a diastolic pressure between 90 and 110 mm Hg) were compared for their platelet activity in vitro and in vivo and for their fibrinolytic activity. Successive measurements were made with the patients lying at rest after they had assumed the erect posture for 10 min and at the end of a 5-min moderately strenuous exercise test.

The effect of ageing on platelet function and fibrinolytic activity.

Twelve healthy male volunteers, mean age twenty-five, range twenty-one to thirty years, and 12 healthy middle-aged male volunteers mean age fifty-eight, range forty-four to seventy-two years, were tested regarding platelet aggregation induced by adenosine diphosphate and fibrinolytic activity, estimated as euglobulin clot lysis time (ECLT), tissue plasminogen activator (t-PA), and the fast-acting inhibitor against t-PA normally referred to as (PAI-1). Platelet aggregation increased significantly in the middle-aged group as compared with the young, as shown by a decrease in ADP thresholds for irreversible aggregation (P < 0.01).

Platelet function and fibrinolytic activity in hypertensive and normotensive sleep apnea patients.

Platelet function and fibrinolytic activity was studied during rest and after ergometric exercise in 13 hypertensive or normotensive patients with obstructive sleep apnea (OSA) and in 10 sex- and weight-matched controls. All patients had undergone a complete polysomnography for the diagnosis of OSA. The controls did not undergo any sleep investigation but had no history of snoring or witnessed apneas during sleep.