B. E. Karlberg

Effect of angiotensin-converting-enzyme inhibition compared with conventional therapy on cardiovascular morbidity and mortality in hypertension: the Captopril Prevention Project (CAPPP) randomised trial

BACKGROUND Angiotensin-converting-enzyme (ACE) inhibitors have been used for more than a decade to treat high blood pressure, despite the lack of data from randomised intervention trials to show that such treatment affects cardiovascular morbidity and mortality. The Captopril Prevention Project (CAPPP) is a randomised intervention trial to compare the effects of ACE inhibition and conventional therapy on cardiovascular morbidity and mortality in patients with hypertension. METHODS CAPPP was a prospective, randomised, open trial with blinded endpoint evaluation. 10,985 patients were enrolled at 536 health centres in Sweden and Finland. Patients aged 25-66 years with a measured diastolic blood pressure of 100 mm Hg or more on two occasions were randomly assigned captopril or conventional antihypertensive treatment (diuretics, beta-blockers). Analysis was by intention-to-treat. The primary endpoint was a composite of fatal and non-fatal myocardial infarction, stroke, and other cardiovascular deaths. FINDINGS Of 5492 patients assigned captopril and 5493 assigned conventional therapy, 14 and 13, respectively, were lost to follow-up. Primary endpoint events occurred in 363 patients in the captopril group (11.1 per 1000 patient-years) and 335 in the conventional-treatment group (10.2 per 1000 patient-years; relative risk 1.05 [95% CI 0.90-1.22], p=0-52). Cardiovascular mortality was lower with captopril than with conventional treatment (76 vs 95 events; relative risk 0.77 [0.57-1-04], p=0.092), the rate of fatal and non-fatal myocardial infarction was similar (162 vs 161), but fatal and non-fatal stroke was more common with captopril (189 vs 148; 1.25 [1-01-1-55]. p=0.044). INTERPRETATION Captopril and conventional treatment did not differ in efficacy in preventing cardiovascular morbidity and mortality. The difference in stroke risk is probably due to the lower levels of blood pressure obtained initially in previously treated patients randomised to conventional therapy.

Randomised trial of effects of calcium antagonists compared with diuretics and β-blockers on cardiovascular morbidity and mortality in hypertension: the Nordic Diltiazem (NORDIL) study

BACKGROUND Calcium antagonists are a first-line treatment for hypertension. The effectiveness of diltiazem, a non-dihydropyridine calcium antagonist, in reducing cardiovascular morbidity or mortality is unclear. We compared the effects of diltiazem with that of diuretics, beta-blockers, or both on cardiovascular morbidity and mortality in hypertensive patients. METHODS In a prospective, randomised, open, blinded endpoint study, we enrolled 10,881 patients, aged 50-74 years, at health centres in Norway and Sweden, who had diastolic blood pressure of 100 mm Hg or more. We randomly assigned patients diltiazem, or diuretics, beta-blockers, or both. The combined primary endpoint was fatal and non-fatal stroke, myocardial infarction, and other cardiovascular death. Analysis was done by intention to treat. FINDINGS Systolic and diastolic blood pressure were lowered effectively in the diltiazem and diuretic and beta-blocker groups (reduction 20.3/18.7 vs 23.3/18.7 mm Hg; difference in systolic reduction p<0.001). A primary endpoint occurred in 403 patients in the diltiazem group and in 400 in the diuretic and beta-blocker group (16.6 vs 16.2 events per 1000 patient-years; relative risk 1.00 [95% CI 0.87-1.15], p=0.97). Fatal and non-fatal stroke occurred in 159 patients in the diltiazem group and in 196 in the diuretic and beta-blocker group (6.4 vs 7.9 events per 1000 patient-years; 0.80 [0.65-0.99], p=0.04) and fatal and non-fatal myocardial infarction in 183 and 157 patients (7.4 vs 6.3 events per 1000 patient-years; 1.16 [0.94-1.44], p=0.17). INTERPRETATION Diltiazem was as effective as treatment based on diuretics, beta-blockers, or both in preventing the combined primary endpoint of all stroke, myocardial infarction, and other cardiovascular death.

The Captopril Prevention Project (CAPPP) in Hypertension—Baseline Data and Current Status

The Captopril Prevention Project (CAPPP) is an ongoing intervention study conducted in 11,019 hypertensive patients in Sweden and Finland. Patients have been randomized to receive either conventional antihypertensive therapy (diuretics and/or beta-blockers) or captopril-based treatment. A prospective, randomized, open, blinded-endpoint evaluation (PROBE) study design is used to compare these two therapeutic regimens as regards cardiovascular morbidity and mortality. The rationale for the CAPPP Study are the many observations of beneficial effects of ACE inhibition, as compared to diuretics and beta-blockers, on intermediary endpoints such as insulin sensitivity, serum lipoproteins, left ventricular hypertrophy and renal function. Captopril has also been shown to be markedly effective in the treatment of left ventricular dysfunction as well as congestive heart failure. The hypothesis is that these differences might result in improved risk reduction when ACE inhibitors are used in the treatment of hypertension. The present paper describes the baseline data and the changes in blood pressure during the first year in the total cohort. During the first year the average blood pressure was reduced by 11/8 mm Hg. A number of substudies have been conducted in the CAPPP Study. In one of these insulin sensitivity was compared in a subgroup of the patients using the euglycemic insulin clamp technique. In another substudy the ACE gene was sequenced and some new polymorphisms were discovered. Several other substudies are in progress or in the planning phase. The main results of the CAPPP Study should be available by mid-1998. Some of the intended anayses of the final results as well as other planned substudies are briefly described here.

Influence of age, sex and blood pressure on the principal endpoints of the Nordic Diltiazem (NORDIL) Study

Background The aim of the Nordic Diltiazem (NORDIL) Study was to compare patients with essential hypertension receiving calcium-antagonist-based treatment with diltiazem and similar patients receiving conventional diuretic/β-blocker-based treatment, with respect to cardiovascular morbidity and mortality. Objective To assess the influence of age, sex, severity of hypertension and heart rate on treatment effects, in a sub-analysis. Methods The NORDIL study was prospective, randomized, open and endpoint-blinded. It enrolled, at health centres in Norway and Sweden, 10 881 patients aged 50–74 years who had diastolic blood pressure (DBP) of 100 mmHg or more. Systolic blood pressure (SBP) and DBP were decreased by 20.3/18.7 mmHg in the diltiazem group and by 23.3/18.7 mmHg in the diuretic/β-blocker group – a significant difference in SBP (P < 0.001). Results The incidence of the primary endpoint – a composite of cardiovascular death, cerebral stroke and myocardial infarction – was similar for the two treatments. Fatal and non-fatal stroke occurred in 159 patients in the diltiazem group and in 196 patients in the conventional treatment group [relative risk (RR) 0.80, 95% confidence interval (CI) 0.65 to 0.99;P = 0.040], whereas there was a non-significant inverse tendency with respect to all myocardial infarction. There were significantly fewer cerebral strokes in patients receiving diltiazem in the subgroups with baseline SBP > 170 mmHg (n = 5420, RR 0.75, 95% CI 0.58 to 0.98;P = 0.032), DBP ⩾ 105 mmHg (n = 5881, RR 0.74, 95% CI 0.57 to 0.97;P = 0.030) and pulse pressure ⩾ 66 mmHg (n = 5461, RR 0.76, 95% CI 0.58 to 0.99, P = 0.041), and more myocardial infarctions in those with heart rate less than 74 beats/min (n = 5303, RR 1.13, 95% CI 1.01 to 1.87;P = 0.040). However, the tendencies for fewer strokes and greater incidence of myocardial infarction were present across subgroups when results were analysed for age, sex, severity of hypertension and heart rate, and treatment–subgroup interaction analyses were not statistically significant. Conclusions Compared with a conventional diuretic/β-blocker-based antihypertensive regimen, there were additional 25% reductions in stroke in the diltiazem-treated patients with blood pressure or pulse pressure greater than the medians, and an increase in myocardial infarction in those with heart rate less than the median. Such findings may be attributable to chance, but the consistency of, in particular, the stroke findings may also suggest an ability of diltiazem, beyond conventional treatment, to prevent cerebral stroke in hypertensive patients with the greatest cardiovascular risk.

Long-term exposure to telmisartan as monotherapy or combination therapy: efficacy and safety.

This multicentre, open-label extension study to four controlled trials involved 888 patients with mild-tomoderate primary hypertension. Patients received telmisartan 40-80 mg once daily with add-on hydrochlorothiazide (HCTZ; 12.5-25 mg) if necessary and/or other antihypertensives to achieve diastolic blood pressure (DBP) control (<90 mmHg). Treatment continued for up to 4 years. At treatment end, 578 (65.1%) patients were on telmisartan monotherapy, 106 (11.9%) were on telmisartan + HCTZ 12.5 mg, 101 (11.4%) were on telmisartan + HCTZ 25 mg, and 103 (11.6%) were on telmisartan + another antihypertensive - HCTZ. Overall, 84.4% (746/884) patients achieved DBP control. The highest proportion of responders was in the telmisartan monotherapy (40 or 80 mg) treatment category (89.0% [511/574 patients]). The mean change in systolic blood pressure (SBP)/DBP from the previous trial baseline to last available trough was-21.2/-17.3 mmHg with telmisartan alone,-24.6/-16.7 mmHg with telmisartan + HCTZ, and-18.7/-14.9 mmHg with telmisartan + another antihypertensive - HCTZ. Most adverse events were of mild-to-moderate intensity and unrelated to treatment. The proportions of patients discontinuing the study due to adverse events, by treatment at onset, were 7.3% (65/888) with telmisartan monotherapy, 6.6% (20/304) with telmisartan + HCTZ and 2.9% (3/103) with telmisartan + another antihypertensive - HCTZ. There were 15 deaths during the study, but none was considered drug related. Thus, telmisartan alone or in combination with other antihypertensives achieved and maintained clinically relevant reductions in DBP and SBP. This long-term analysis supports the favourable efficacy and safety profile of telmisartan both as monotherapy and in combination with other antihypertensive drugs.

Efficacy and safety of a new long-acting drug combination, trandolapril/verapamil as compared to monotherapy in primary hypertension

Objective: To evaluate the clinical efficacy and safety of a new antihypertensive drug combination of trandolapril/verapamil compared to monotherapy with verapamil or trandolapril, in patients with mild to moderate primary hypertension. Design: A multicentre, prospective, randomized, double-blind, controlled cross-over study with specific statistical considerations. Settings: Eighteen primary health care centres and out-patient hospital clinics in Sweden. Patients: Two hundred and twenty-six outpatients with uncomplicated primary hypertension with a baseline sitting diastolic blood pressure (BP) between 95 and 115 mmHg. Interventions: After a 4-week placebo period, patients were randomized to treatment for 8 weeks with trandolapril/verapamil (2 mg/180 mg) or each drug alone (verapamil 240 mg, trandolapril 2 mg) for 8 weeks. Main outcome measures: Treatment responses (blood pressure (BP) fall and rate pressure product) to the three regimens with statistical comparison and also in relation to plasma concentrations of active renin (AR). Adverse events and safety were also evaluated. Results: The mean BP fall was significantly greater with the combination (20/15 mmHg), p < 0.00054, as compared to both trandolapril (14/11 mmHg) or verapamil (13/11) mmHg. The difference between verapamil and trandolapril was not significant. Rate pressure product decreased significantly more on the combination, p < 0.001, than on trandolapril or verapamil alone. Treatment response to trandolapril was positively correlated to initial AR (r = 0.30-0.43). All treatments were well tolerated and safe. Conclusions: The new fixed drug combination trandolapril/verapamil was superior to monotherapy with either of these drugs alone regarding reduction of both BP and rate pressure product. This combination can be safely and effectively used for the treatment of mild to moderate primary hypertension.