Sex Difference in Patients With Ischemic Heart Failure Undergoing Surgical Revascularization: Results From the STICH Trial (Surgical Treatment for Ischemic Heart Failure).

BACKGROUND: Female sex is conventionally considered a risk factor for coronary artery bypass grafting (CABG) and has been included as a poor prognostic factor in multiple cardiac operative risk evaluation scores. We aimed to investigate the association of sex and the long-term benefit of CABG in patients with ischemic left ventricular dysfunction enrolled in the prospective STICH trial (Surgical Treatment for Ischemic Heart Failure Study). METHODS: The STICH trial randomized 1212 patients (148 [12%] women and 1064 [88%] men) with coronary artery disease and left ventricular ejection fraction ≤35% to CABG+medical therapy (MED) versus MED alone. Long-term (10-year) outcomes with each treatment were compared according to sex. RESULTS: At baseline, women were older (63.4 versus 59.3 years; P=0.016) with higher body mass index (27.9 versus 26.7 kg/m2; P=0.001). Women had more coronary artery disease risk factors (diabetes mellitus, 55.4% versus 37.2%; hypertension, 70.9% versus 58.6%; hyperlipidemia, 70.3% versus 58.9%) except for smoking (13.5% versus 21.8%) and had lower rates of prior CABG (0% versus 3.4%; all P<0.05) than men. Moreover, women had higher New York Heart Association class (class III/IV, 66.2% versus 57.0%), lower 6-minute walk capacity (300 versus 350 m), and lower Kansas City Cardiomyopathy Questionnaire overall summary scores (51 versus 63; all P<0.05). Over 10 years of follow-up, all-cause mortality (49.0% versus 65.8%; adjusted hazard ratio, 0.67; 95% confidence interval, 0.52-0.86; P=0.002) and cardiovascular mortality (34.3% versus 52.3%; adjusted hazard ratio, 0.65; 95% confidence interval, 0.48-0.89; P=0.006) were significantly lower in women compared with men. With randomization to CABG+MED versus MED treatment, there was no significant interaction between sex and treatment group in all-cause mortality, cardiovascular mortality, or the composite of all-cause mortality or cardiovascular hospitalization (all P>0.05). In addition, surgical deaths were not statistically different (1.5% versus 5.1%; P=0.187) between sexes among patients randomized to CABG per protocol as initial treatment. CONCLUSIONS: Sex is not associated with the effect of CABG+MED versus MED on all-cause mortality, cardiovascular mortality, the composite of death or cardiovascular hospitalization, or surgical deaths in patients with ischemic left ventricular dysfunction. Thus, sex should not influence treatment decisions about CABG in these patients. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00023595.

Prevalence and prognostic significance of low QRS voltage among the three main types of cardiac amyloidosis.

Low voltage is classically reported as an electrocardiographic (ECG) finding in cardiac amyloidosis (CA). We evaluated electrocardiograms to determine the prevalence of low voltage and its association with outcomes. Electrocardiograms in 200 patients with CA were reviewed. The presence of low voltage was assessed by all limb leads≤0.5 mV, all precordial leads≤1.0 mV, or Sokolow index≤.5 mV, and the association with time to adverse outcomes, including hospitalization, orthotopic heart transplant, and death, was assessed by the Cox proportional hazards model. Low voltage prevalence was 60% when using Sokolow index≤.5 mV, 34% by QRS amplitude≤0.5 mV in each limb lead, and 13% when ≤1.0 mV in each precordial lead with no differences in prevalence noted by the type of amyloid. Apart from atrial fibrillation and second-degree atrioventricular block being more common in wild type transthryretin cardiac amyloid (ATTRwt), the prevalence of ECG findings was similar among the 3 types of amyloid. Sokolow≤1.5 mV (HR 1.690; 95% CI of 1.069 to 2.672; p=0.0246) was independently associated with adverse outcomes. In conclusion, among the 3 main types of CA, the prevalence of low voltage is dependent on the method used for defining low voltage. Sokolow index≤1.5 mV indicated the highest prevalence and was associated with adverse outcomes in CA. Our data suggest that low voltage is a relatively late finding in CA and may not be useful for early identification.