Predictors of long-term outcomes in symptomatic hypertrophic obstructive cardiomyopathy patients undergoing surgical relief of left ventricular outflow tract obstruction.

Desai MY ，Bhonsale A ，Smedira NG ，Naji P ，Thamilarasan M ，Lytle BW ，Lever HM ... -  《-》

Predictors of long-term outcomes in patients with hypertrophic cardiomyopathy undergoing cardiopulmonary stress testing and echocardiography.

Patients with hypertrophic cardiomyopathy (HCM) have exercise intolerance due to left ventricular outflow tract (LVOT) obstruction, mitral regurgitation, and left ventricular dysfunction. We sought to study predictors of outcomes in HCM patients undergoing cardiopulmonary stress testing (CPT). We studied 1,005 HCM patients (50 ± 14 years, 64% men, 77% on β-blockers) who underwent CPT with echocardiography. Clinical, echocardiographic, and exercise variables (peak oxygen consumption [VO2] and heart rate recovery [HRR] at first minute postexercise) were recorded. End point was a composite of death, appropriate defibrillator discharges, resuscitated sudden death, stroke, and heart failure admission. Mean left ventricular ejection fraction (LVEF), postexercise LVOT gradient, and peak VO2 were 62% ± 6%, 92 ± 51 mm Hg, and 21 ± 6 mL kg(-1) min(-1), respectively. Despite 789 patients (78%) being in New York Heart Association classes I to II, only 8% achieved >100% age-gender predicted peak VO2, whereas 77% and 15% achieved 50% to 100% and <50%, respectively. Left ventricular outflow tract gradient ≥30 mm Hg was observed in 83% patients, whereas 23% had abnormal HRR. More than 5.5 ± 4 years, there were 94 (9%) events; 511 (50%) patients underwent surgery for LVOT obstruction. Multivariable Cox proportional analysis demonstrated % age-gender predicted peak VO2 (hazard ratio [HR] 0.96 [0.93-0.98]), normal vs abnormal HRR (HR 0.48 [0.32-0.73]), higher LVEF (HR 0.96 [0.93-0.98]), surgery (0.53 [0.33-0.83]), and atrial fibrillation (HR 1.65 [1.04-2.60]) were associated with outcomes (all P < .05). In HCM patients undergoing CPT, a higher % of achieved age-gender predicted VO2 and surgical relief of LVOT obstruction were associated with better outcomes, whereas abnormal HRR, atrial fibrillation, and lower LVEF were associated with worse outcomes.

Masri A ，Pierson LM ，Smedira NG ，Agarwal S ，Lytle BW ，Naji P ，Thamilarasan M ，Lever HM ，Cho LS ，Desai MY ... -  《-》

Exercise echocardiography in asymptomatic HCM: exercise capacity, and not LV outflow tract gradient predicts long-term outcomes.

This study sought to assess long-term outcomes in asymptomatic or minimally symptomatic patients with hypertrophic cardiomyopathy (HCM) who underwent exercise echocardiography, without invasive therapies for relief of left ventricular outflow tract (LVOT) obstruction. Many HCM patients present with LVOT obstruction, mitral regurgitation (MR), and diastolic dysfunction, often requiring invasive therapies for symptomatic relief. However, a significant proportion of truly asymptomatic patients can be closely monitored. In HCM patients, exercise echocardiography has been shown to be a useful assessment of functional capacity and risk stratification. We included 426 HCM patients (44 ± 14 years; 78% men) undergoing exercise echocardiography, excluding hypertensive heart disease of elderly, ejection fraction <50% and invasive therapy (myectomy or alcohol ablation) during follow-up. Clinical, echocardiographic (LV thickness, LVOT gradient, and MR) and exercise variables (percent of age-sex predicted metabolic equivalents [METs] and heart rate recovery [HRR] at 1 min post-exercise) were recorded. A composite endpoint of death, appropriate internal defibrillator discharge, and admission for congestive heart failure was recorded. Patients were asymptomatic or minimally symptomatic on history, but 82% of patients achieved <100% of age-sex predicted METs, and 43% had ≥II+ post-stress MR. The mean LV septal thickness, post-exercise LVOT gradient, and HRR were 2.0 ± 0.5 cm, 62 ± 47 mm Hg, and 31 ± 14 beats/min, respectively. During a mean follow-up of 8.7 ± 3 years, there were 52 events (12%). Patients achieving >100% of age-sex predicted METs had 1% event rate versus 12% in those achieving <85%. On stepwise multivariate survival analysis, percent of age-sex predicted METs (hazard ratio [HR]: 0.76; 95% confidence interval [CI]: 0.64 to 0.90), abnormal HRR (HR: 0.89; 95% CI: 0.82 to 0.97), and atrial fibrillation (HR: 2.73; 95% CI: 1.30 to 5.74) (overall, p < 0.001) independently predicted outcomes. In asymptomatic or minimally symptomatic HCM patients, exercise stress testing provides excellent risk stratification, with a low event rate in patients achieving >100% of predicted METs.

Desai MY ，Bhonsale A ，Patel P ，Naji P ，Smedira NG ，Thamilarasan M ，Lytle BW ，Lever HM ... -  《-》

Characteristics and surgical outcomes of symptomatic patients with hypertrophic cardiomyopathy with abnormal papillary muscle morphology undergoing papillary muscle reorientation.

In patients with hypertrophic cardiomyopathy with bifid hypermobile papillary muscles and a dynamic left ventricular outflow tract gradient, we performed surgical papillary muscle reorientation, fixing the mobile papillary muscle to the posterior left ventricle to reduce mobility. We report the outcomes of patients with hypertrophic cardiomyopathy undergoing surgical papillary muscle reorientation versus those of patients undergoing standard surgical procedures. We studied 204 consecutive patients with hypertrophic cardiomyopathy undergoing surgical intervention (after consensus decision) for symptomatic left ventricular outflow tract gradient. Preoperative and postoperative maximal (resting/provocable) left ventricular outflow tract gradients were recorded by using echocardiographic analysis. The population was divided into 3 groups: (1) isolated myectomy (n = 143; age, 54 +/- 14 years; 48% men), (2) myectomy plus mitral valve repair/replacement (n = 39; age, 54 +/- 13 years; 54% men), and (3) papillary muscle reorientation with or without myectomy (n = 22; age, 50 +/- 14 years; 59% men). The mean preoperative (103 +/- 32, 103 +/- 32, and 114 +/- 36 mm Hg; P = .3) and predischarge (15 +/- 18, 14 +/- 14, and 16 +/- 21 mm Hg; P = .9) maximal left ventricular outflow tract gradients were similar. There were no deaths either in the hospital or at 30 days. At a median follow-up of 166 days (interquartile range, 74-343 days), 21 of 22 patients in group 3 were asymptomatic. One patient in group 3 had a symptomatic left ventricular outflow tract gradient (87 mm Hg) requiring mitral valve replacement. In patients with hypertrophic cardiomyopathy with bifid hypermobile papillary muscles (even with a basal septal thickness <1.5 cm), papillary muscle reorientation reduces the symptomatic left ventricular outflow tract gradient. Long-term outcomes need to be ascertained.

Kwon DH ，Smedira NG ，Thamilarasan M ，Lytle BW ，Lever H ，Desai MY ... -  《-》

Symptom assessment and exercise impairment in surgical decision making in hypertrophic obstructive cardiomyopathy: Relationship to outcomes.

We sought to assess the long-term outcomes in patients with hypertrophic cardiomyopathy and severe left ventricular outflow tract obstruction, in whom the decision regarding surgery (vs conservative management) was based on assessment of symptoms or exercise capacity. This was an observational study of 1530 patients with hypertrophic cardiomyopathy (aged 50 ± 13 years, 63% were men) with severe left ventricular outflow tract obstruction (excluding those aged <18 years, with left ventricular ejection fraction <50%, and with left ventricular outflow tract gradient <30 mm Hg). A composite end point of death (excluding noncardiac causes) and/or implantable defibrillator discharge was assessed. Coronary artery disease, family history of hypertrophic cardiomyopathy, and syncope were present in 15%, 17%, and 18% of patients, respectively, whereas 73% patients were in New York Heart Association class II or greater. Mean left ventricular ejection fraction, basal septal thickness, and left ventricular outflow tract gradient (resting or provocable) were 62% ± 5%, 2.2 ± 1 cm, and 101 ± 39 mm Hg, respectively. A total of 858 patients (56%) underwent exercise echocardiography, of whom 503 (59%) had exercise capacity impairment. At 8.1 ± 6 years, 990 patients (65%) underwent surgical relief of left ventricular outflow tract obstruction, and 540 patients (35%) did not. There were 156 events (10%) (134 deaths), with 0% 30-day mortality in the surgical group. On multivariable Cox proportional hazard analysis, increasing age (hazard ratio [HR], 1.20), coronary artery disease (HR, 1.68), worse New York Heart Association class (HR, 1.46), and atrial fibrillation (HR, 1.90) predicted higher events, whereas surgery (time-dependent covariate HR, 0.57) was associated with improved event-free survival (all P < .01). In patients with hypertrophic cardiomyopathy and severe left ventricular outflow tract obstruction, in whom the decision regarding surgery was based on the presence of intractable symptoms and impaired exercise capacity, surgery was associated with significant improvement in long-term composite outcomes.

Desai MY ，Smedira NG ，Bhonsale A ，Thamilarasan M ，Lytle BW ，Lever HM ... -  《-》