Efficacy and safety of PDE-5 inhibitor tadalafil in pulmonary arterial hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a life threatening disease for which phosphodiesterase-5 inhibitor sildenafil is recently approved. We aimed to evaluate the efficacy and safety of tadalafil, a long acting congener of sildenafil, in treatment of PAH related to previous left to right shunt lesions. METHODS: In this blinded, cross over study, 11 patients with severe PAH related to congenital left to right shunt lesions (Eisenmenger syndrome) were randomly assigned to tadalafil (20 mg daily) or placebo for 4 weeks period, separated by a wash out period of at least 2 weeks. They were symptomatic with a six minute walk distance (6MWD)>or=50 m. The change in 6MWD, echo-Doppler determined pulmonary artery systolic pressure (PASP), WHO Class and modified Borg Dyspnea Index (BDI) were assessed after each therapy. RESULTS: Eight patients who completed the study protocol were analyzed. Tadalafil was associated with a significant increase in 6MWD (mean 409.25 SD 40.25 m vs 319.37 SD 42.39 m, p<0.0001), reduction in PASP (88.75 SD 23.26 mmHg vs 109.5 SD 23.78 mmHg, p<0.0001), improvement in BDI (4.62 SD 2.56 vs 6.37 SD 2.61, p=0.021) and WHO Class (6 patients vs 2 patients), compared to placebo. Tadalafil was well tolerated with no significant untoward effects. CONCLUSIONS: Tadalafil, in patients with PAH related to previous congenital left to right shunt lesions, lead to a significant improvement in exercise capacity (6MWD), PASP and WHO Class with reduced perceived exertion and was well tolerated.

Terminalia arjuna reverses impaired endothelial function in chronic smokers.

BACKGROUND: Smoking, largely through increased oxidative stress, causes endothelial dysfunction which is an early key event in atherosclerosis. Smoking cessation and antioxidant vitamin therapy are shown to have beneficial role by restoring altered endothelial physiology. The present study was aimed to determine whether Terminalia arjuna, an Indian medicinal plant with potent antioxidant constituents, would improve endothelial dysfunction in smokers. METHODS AND RESULTS: Eighteen healthy male smokers (age 28.16+/-9.45 years) and equal number of age-matched non-smoker controls participated in the study. The baseline brachial artery reactivity studies were performed using high frequency ultrasound according to standard protocol under identical conditions to determine endothelium-dependent, flow-mediated dilation and endothelium-independent nitroglycerine-mediated dilation. The two groups were matched regarding age, body mass index, blood pressure, serum cholesterol, mean resting vessel diameters and post-occlusion flow velocities (all p=NS). While flow-mediated dilation was significantly impaired amongst smokers compared to controls (4.71+/-2.22 v. 11.75+/-5.94%, p <0.005), the nitroglycerine-mediated dilation was similar in the two groups (20.35+/-3.89 v. 19.68+/-3.74%, p=NS). Subsequently the smokers were given Terminalia arjuna (500 mg q8h) or matching placebo randomly in a double blind cross-over design for two weeks each, followed by repetition of brachial artery reactivity studies to determine various parameters including flow-mediated dilation after each period. There was no significant difference as regards vessel diameter and flow velocities between the two therapies. However, the flow-mediated dilation showed significant improvement from baseline values after Terrminalia arjuna therapy but not with placebo (9.31+/-3.74 v. 5.17+/-2.42%, p <0.005). CONCLUSIONS: Smokers have impaired endothelium-dependent but normal endothelium-independent vasodilation as determined by brachial artery reactivity studies. Further, Terrminalia arjuna therapy for two weeks leads to significant regression of this endothelial abnormality amongst smokers.

The efficacy and tolerability of sildenafil in patients with moderate-to-severe pulmonary hypertension.

BACKGROUND: Pulmonary arterial hypertension is a life-threatening disease for which continuous intravenous infusion of prostacyclin has proved effective. However, it carries the risk of serious complications arising from the complex delivery system. Prostacyclin analogs, endothelin antagonists, and the phosphodiesterase-5 inhibitor sildenafil are emerging promising therapies. This study was aimed at evaluating the utility of oral sildenafil in patients with pulmonary hypertension of varied etiology, poorly controlled on conventional treatment. METHODS AND RESULTS: Ten consecutive patients with pulmonary hypertension, either primary or related to previous left-to-right shunts, thromboembolism, or interstitial lung disease, poorly controlled on conventional therapy such as warfarin, calcium antagonists, digitalis, and diuretics, were included. A thorough clinical, laboratory, and comprehensive echo Doppler evaluation was performed before enrollment in the trial to establish the diagnosis and obtain baseline data. Subjects received sildenafil 25 mg 8 hourly, or a matching placebo for two weeks each, in a randomized, double-blind, crossover design. A run-in period of two weeks was permitted between the two therapies during which patients continued to receive the conventional therapy without any vasodilator. At the end of each therapy period, the patients were evaluated for symptoms, New York Heart Association class, distance covered during the 6 min walk test, rating of modified Borg dyspnea score, and systolic pulmonary artery pressure using echo Doppler. The differences in the above variables at the end of sildenafil and placebo therapies were compared. Nine patients completed the study protocol. Sildenafil, compared to placebo, was associated with improved exercise tolerance as determined by the 6 min walk test (266.67+/-131.45 m v. 170+/-105 m; p<0.005), decrease in modified Borg dyspnea score (3.56+/-1.01 v. 5.11+/-1.45; p<0.01), decrease in Doppler-estimated pulmonary artery systolic pressures (55.33+/-16.52 mmHg v. 75.33+/-19.75 mmHg; p<0.005), improvement in New York Heart Association class (2 patients), and improvement in symptoms. Sildenafil was well tolerated with no untoward effects; further, no significant changes in heart rate or blood pressure occurred during the study period. CONCLUSIONS: Sildenafil improves exercise capacity and symptoms, and decreases pulmonary artery pressures in patients with primary or secondary pulmonary hypertension of varied etiology.

Efficacy of Terminalia arjuna in chronic stable angina: a double-blind, placebo-controlled, crossover study comparing Terminalia arjuna with isosorbide mononitrate.

BACKGROUND: Terminalia arjuna, an Indian medicinal plant, has been reported to have beneficial effects in patients with ischemic heart disease in a number of small, open studies. The need for a double-blind, randomized, placebo-controlled study with adequate sample size has long been felt. The bark extract (IPC-53) contains acids (arjunic acid, terminic acid), glycosides (arjunetin arjunosides I-IV), strong antioxidants (flavones, tannins, oligomeric proanthocyanidins), minerals. etc. and exhibits antifailure and anti-ischemic properties. METHODS AND RESULTS: Fifty-eight males with chronic stable angina (NYHA class II-III) with evidence of provocable ischemia on treadmill exercise test received Terminalia arjuna (500 mg 8 hourly), isosorbide mononitrate (40 mg/daily) or a matching placebo for one week each, separated by a wash-out period of at least three days in a randomized, double-blind, crossover design. They underwent clinical, biochemical and treadmill exercise evaluation at the end of each therapy which were compared during the three therapy periods. Terminalia arjuna therapy was associated with significant decrease in the frequency of angina and need for isosorbide dinitrate (5.69+/-6.91 mg/week v. 18.22+/-9.29 mg/week during placebo therapy, p<0.005). The treadmill exercise test parameters improved significantly during therapy with Terminalia arjuna compared to those with placebo. The total duration of exercise increased (6.14+/-2.51 min v. 4.76+/-2.38 min, p<0.005), maximal ST depression during the longest equivalent stages of submaximal exercise decreased (1.41+/-0.55 mm v. 2.21+/-0.56 mm, p<0.005), time to recovery decreased (6.49+/-2.37 min v. 9.27+/-3.39 min, p<0.005) and higher double products were achieved (25.75+/-4.81x10(3) v. 23.11+/-4.83x10(3), p<0.005) during Terminalia arjuna therapy. Similar improvements in clinical and treadmill exercise test parameters were observed with isosorbide mononitrate compared to placebo therapy. No significant differences were observed in clinical or treadmill exercise test parameters when Terminalia arjuna and isosorbide mononitrate therapies were compared. No significant untoward effects were reported during Terminalia arjuna therapy. CONCLUSIONS: Terminalia arjuna bark extract, 500 mg 8 hourly, given to patients with stable angina with provocable ischemia on treadmill exercise, led to improvement in clinical and treadmill exercise parameters as compared to placebo therapy. These benefits were similar to those observed with isosorbide mononitrate (40 mg/day) therapy and the extract was well tolerated. Limitations of this study include applicability of the results to only men with chronic stable angina but not necessarily to women, as they were not studied.