No abstract

clinicaltrials.gov Identifier: NCT00387231.

BACKGROUND Smoking is a major risk factor for the development of atherosclerosis. Because endothelial dysfunction may be a marker for future atherosclerosis, we investigated the effects of smoking on endothelium-dependent control of vascular tone. METHODS AND RESULTS The effects of brachial arterial infusions of NG-monomethyl-L-arginine (L-NMMA), a nitric oxide synthesis inhibitor; sodium nitroprusside; endothelin-1; and norepinephrine on forearm blood flow (strain-gauge plethysmography) were compared in 29 long-term smokers and 16 nonsmokers. The acute effects of smoking on systemic hemodynamics, plasma catecholamines, and forearm vascular responses to these compounds were investigated in smokers only. Smokers did not differ from nonsmokers (n = 16) regarding the vascular effects of sodium nitroprusside (n = 13) or vasoconstriction due to norepinephrine and endothelin-1 (n = 16). Low-dose endothelin-1-induced vasodilation, believed to reflect endothelial prostacyclin or nitric oxide release, was absent in smokers (n = 16), and their increase of forearm vascular resistance (FVR) after L-NMMA (n = 13) was impaired (35.6 +/- 27.9% versus 118.8 +/- 43.2%, P < .001). Short-term smoking (n = 11) increased blood pressure, heart rate, and plasma epinephrine concentrations (P < .05 or less); enhanced endothelin-1-induced vasoconstriction (delta FVR, 457 +/- 192% versus 254 +/- 143%, P < .01); and decreased norepinephrine-induced vasoconstriction (P < .05), but had no effect on the other interventions. CONCLUSIONS Long-term smoking is associated with a diminished nitric oxide-dependent component of basal vascular tone and an impaired endothelium-dependent vasodilator response to low-dose endothelin-1 and short-term smoking enhances endothelin-1-induced vasoconstriction. Impaired endothelial control of vascular tone might reflect impairment of normal antiatherosclerotic endothelial functions in smokers, but the relevance of smoking-induced enhancement of endothelin-1 vasoconstriction remains to be determined.

In view of the high risk of sudden cardiac death and the prognostic importance of complex ventricular ectopic activity, the effects of prophylactic antiarrhythmic treatment were investigated prospectively in patients with persisting asymptomatic complex arrhythmias after myocardial infarction. End points were total mortality and arrhythmic events (sudden death, sustained ventricular tachycardia and ventricular fibrillation). Of 1,220 consecutively screened survivors of myocardial infarction, 312 had Lown class 3 or 4b arrhythmia on 24 h electrocardiographic recordings before hospital discharge and consented to the study. They were randomized to individualized antiarrhythmic treatment (Group 1, n = 100), treatment with low dose amiodarone, 200 mg/day (Group 2, n = 98) or no antiarrhythmic therapy (Group 3 [control group], n = 114). During the 1 year follow-up period, 10 patients in Group 1 died, as did 5 in Group 2 and 15 in Group 3. On the basis of an intention to treat analysis, the probability of survival of patients given amiodarone was significantly greater than that of control patients (p less than 0.05). In addition, arrhythmic events were significantly reduced by amiodarone (p less than 0.01). These effects were less marked and not significant for individually treated patients (Group 1). These findings suggest that low dose amiodarone decreases mortality in the 1st year after myocardial infarction in patients at high risk of sudden death.

AimsSpecific causes and modes of death (COD and MOD) of patients with heart failure (HF) are not well described, particularly in those with preserved ejection fraction .45% (HFPEF) and at old age. Thus, using the database of the TIME-CHF study, patients with HFPEF were compared with those with reduced ejection fraction ≤45% (HFREF), and patients ≥75 with those 60 -74 years of age to identify MOD and COD, predictors of death, and event rates before death as compared with survivors. Methods and resultsDuring the 18-month follow-up, 132/622 patients (21%) died, with similar rates in patients with HFPEF and HFREF and a trend to higher rates in patients aged ≥75 years (24% vs. 17%, P ¼ 0.06). COD and MOD (ACME system) were not different in the age groups. COD was more often non-cardiovascular in HFPEF patients than in HFREF patients (33% vs. 16%, P , 0.05) and cardiac MOD were more frequent in HFREF patients (75% vs. 56%, P , 0.05), mainly due to more sudden deaths (25% vs. 7%, P , 0.05). Patients who died experienced a median of four adverse events (interquartile range 1-7) and one (0-1) hospitalization within 60 days prior to death compared with 0.7 (0.4-1.4) and 0.1 (0.0 -0.2) during a randomly selected 60 days in survivors (all P , 0.0001). ConclusionDespite similar 18-month mortality in patients with HFREF and those with HFPEF, important differences in COD and MOD were found which were not observed between the two age groups. A high rate of adverse events and hospitalizations preceded death. These observations may be relevant for the management of HF patients.--