Ventricular Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy (Analysis Spanning 60 Years Of Practice): AJC Expert Panel.

Surgical myectomy remains the time-honored primary treatment for hypertrophic cardiomyopathy patients with drug refractory limiting symptoms due to LV outflow obstruction. Based on >50 years experience, surgery reliably reverses disabling heart failure by permanently abolishing mechanical outflow impedance and mitral regurgitation, with normalization of LV pressures and preserved systolic function. A consortium of 10 international currently active myectomy centers report about 11,000 operations, increasing significantly in number over the most recent 15 years. Performed in experienced multidisciplinary institutions, perioperative mortality for myectomy has declined to 0.6%, becoming one of the safest currently performed open-heart procedures. Extended myectomy relieves symptoms in >90% of patients by ≥ 1 NYHA functional class, returning most to normal daily activity, and also with a long-term survival benefit; concomitant Cox-Maze procedure can reduce the number of atrial fibrillation episodes. Surgery, preferably performed in high volume clinical environments, continues to flourish as a guideline-based and preferred high benefit: low treatment risk option for adults and children with drug refractory disabling symptoms from obstruction, despite prior challenges: higher operative mortality/skepticism in 1960s/1970s; dual-chamber pacing in 1990s, alcohol ablation in 2000s, and now introduction of novel negative inotropic drugs potentially useful for symptom management.

Outcomes in Patients With Obstructive Hypertrophic Cardiomyopathy and Concomitant Aortic Stenosis Undergoing Surgical Myectomy and Aortic Valve Replacement.

Background Hypertrophic cardiomyopathy (HCM) and aortic stenosis can cause obstruction to the flow of blood out of the left ventricular outflow tract into the aorta, with obstructive HCM resulting in dynamic left ventricular outflow tract obstruction and moderate or severe aortic stenosis causing fixed obstruction caused by calcific degeneration. We sought to report the characteristics and longer-term outcomes of patients with severe obstructive HCM who also had concomitant moderate or severe aortic stenosis requiring surgical myectomy and aortic valve replacement. Methods and Results We studied 191 consecutive patients (age 67±6 years, 52% men) who underwent myectomy and aortic valve (AV) replacement (90% bioprosthesis) at our center between June 2002 and June 2018. Clinical and echo data including left ventricular outflow tract gradient and indexed AV area were recorded. The primary outcome was death. Prevalence of hypertension (63%) and hyperlipidemia (75%) were high, with a Society of Thoracic Surgeons score of 5±4, and 70% of participants had no HCM-related sudden death risk factors. Basal septal thickness and indexed AV area were 1.9±0.4 cm and 0.72±0.2 cm2/m2, respectively, while 100% of patients had dynamic left ventricular outflow tract gradient >50 mm Hg. At 6.5±4 years, 52 (27%) patients died (1.5% in-hospital deaths). One-, 2-, and 5-year survival in the current study sample was 94%, 91%, and 83%, respectively, similar to an age-sex-matched general US population. On multivariate Cox survival analysis, age (hazard ratio [HR], 1.65; 95% CI, 1.24-2.18), chronic kidney disease (HR, 1.58; 95% CI, 1.21-2.32), and right ventricular systolic pressure on preoperative echocardiography (HR, 1.28; 95% CI, 1.05-1.57) were associated with longer-term mortality, but traditional HCM risk factors did not. Conclusions In symptomatic patients with severely obstructive HCM and moderate or severe aortic stenosis undergoing a combined surgical myectomy and AV replacement at our center, the observed postoperative mortality was significantly lower than the expected mortality, and the longer-term survival was similar to a normal age-sex-matched US population.

Outcomes in Guideline-Based Class I Indication Versus Earlier Referral for Surgical Myectomy in Hypertrophic Obstructive Cardiomyopathy.

Background In patients with obstructive hypertrophic cardiomyopathy, surgical myectomy (SM) is indicated for severe symptoms. We sought to compare long-term outcomes of patients with obstructive hypertrophic cardiomyopathy where SM was based on guideline-recommended Class I indication (Functional Class or FC ≥3 or angina/exertional syncope despite maximal medical therapy) versus earlier (FC 2 and/or impaired exercise capacity on exercise echocardiography with severe obstruction). Methods and Results We studied 2268 consecutive patients (excluding <18 years, ≥ moderate aortic stenosis and subaortic membrane, 56±14 years, 55% men), who underwent SM at our center between June 2002 and March 2018. Clinical data, including left ventricular outflow tract gradient, were recorded. Death and/or appropriate internal defibrillator discharge were primary composite end points. One thousand three hundred eighteen (58%) patients met Class I indication and 950 (42%) underwent earlier surgery; 222 (10%) had a history of obstructive coronary artery disease. Basal septal thickness, and resting and maximal left ventricular outflow tract gradient were 2.0±0.3 cm, 61±44 mm Hg, and 100±31 mm Hg, respectively. At 6.2±4 years after SM, 248 (11%) had composite events (13 [0.6%] in-hospital deaths). Age (hazard ratio [HR], 1.61; 95% CI, 1.26-1.91), obstructive coronary artery disease (HR, 1.46; 95% CI, 1.06-1.91), and Class I versus earlier SM (HR, 1.61; 95% CI, 1.14-2.12) were associated with higher primary composite events (all P<0.001). Earlier surgery had better longer-term survival (similar to age-sex-matched normal population) versus surgery for Class I indication (76 [8%] versus 193 [15%], P<0.001). Conclusions In patients with obstructive hypertrophic cardiomyopathy, earlier versus surgery for Class I indication had a better long-term survival, similar to the age-sex-matched US population.

Prediction of sudden death risk in obstructive hypertrophic cardiomyopathy: Potential for refinement of current criteria.

BACKGROUND: In patients with hypertrophic cardiomyopathy (HCM), the use of an implantable cardioverter defibrillator (ICD) can prevent sudden cardiac death (SCD). In patients with obstructive HCM, we sought to determine the prognostic utility of European Society of Cardiology (ESC) SCD risk score and to evaluate whether additional factors modulate SCD risk. METHODS: We studied 1809 consecutive patients with obstructive HCM (mean age, 50 ± 14 years; 63% males; mean maximal outflow tract gradient, 93 ± 40 mm Hg). Major SCD risk factors were recorded (0, 1, or ≥2) and % 5-year ESC SCD risk score was calculated. The need for surgical myectomy and a composite endpoint (SCD and/or appropriate ICD discharge) were recorded. RESULTS: The distribution of major SCD risk factors was 0 in 65% of the patients, 1 in 26%, and ≥2 in 8%. The 5-year ESC risk was low (<4%) in 65% of the patients, intermediate (4%-6%) in 18%, and high (>6%) in 17%. Surgery was performed in 1160 patients (64%), and 361 (20%) had AF. At a mean of 8.8 ± 4 years, 169 patients had a composite event (154 SCDs). At 5 years, despite a wide range of expected events (2.5%-9%), the observed events ranged from 4.6% to 5% across 3 SCD risk categories (Hosmer-Lemeshow P = .32). On multivariable competing-risk analysis, myectomy (subdistribution hazard ratio [sHR], 0.69; 95% confidence interval [CI], 0.47-0.83) was associated with lower risk of longer-term composite events (P < .01), whereas ESC SCD risk score was not (sHR, 1.31; 95% CI, 0.75-2.25; P = .36). CONCLUSIONS: In patients with obstructive HCM, despite a wide range of expected 5-year primary event rate, the observed primary events were similar across the 3 ESC SCD risk categories, with myectomy mitigating SCD risk. In patients with obstructive HCM, SCD risk may need to be refined for patients following myectomy.

Incremental Prognostic Utility of Left Ventricular Global Longitudinal Strain in Hypertrophic Obstructive Cardiomyopathy Patients and Preserved Left Ventricular Ejection Fraction.

BACKGROUND: In obstructive hypertrophic cardiomyopathy patients with preserved left ventricular (LV) ejection fraction, we sought to determine whether LV global longitudinal strain (LV-GLS) provided incremental prognostic utility. METHODS AND RESULTS: We studied 1019 patients with documented hypertrophic cardiomyopathy (mean age, 50±12 years; 63% men) evaluated at our center between 2001 and 2011. We excluded age <18 years, maximal LV outflow tract gradient <30 mm Hg, bundle branch block or atrial fibrillation, past pacemaker/cardiac surgery, including myectomy/alcohol ablation, and obstructive coronary artery disease. Average resting LV-GLS was measured offline on 2-, 3-, 4-chamber views using Velocity Vector Imaging (Siemens, Malvern, PA). Outcome was a composite of cardiac death and appropriate internal defibrillator (implantable cardioverter defibrillator) discharge. Maximal LV thickness, LV ejection fraction, indexed left atrial dimension, rest and maximal LV outflow tract gradient, and LV-GLS were 2.0±0.2 cm, 62±4%, 2.2±4 cm/m2, 52±42 mm Hg, 103±36 mm Hg, and -13.6±4%. During 9.4±3 years of follow-up, 668 (66%), 166 (16%), and 122 (20%), respectively, had myectomy, atrial fibrillation, and implantable cardioverter defibrillator implantation, whereas 69 (7%) had composite events (62 cardiac deaths). Multivariable competing risk regression analysis revealed that higher age (subhazard ratio, 1.04 [1.02-1.07]), AF during follow-up (subhazard ratio, 1.39 [1.11-1.69]), and worsening LV-GLS (subhazard ratio, 1.11 [1.05-1.22]) were associated with worse outcomes, whereas myectomy (subhazard ratio, 0.44 [0.25-0.72]) was associated with improved outcomes (all P<0.01). Sixty-one percent of events occurred in patients with LV-GLS worse than median (-13.7%). CONCLUSIONS: In obstructive hypertrophic cardiomyopathy patients with preserved LV ejection fraction, abnormal LV-GLS was independently associated with higher events, whereas myectomy was associated with improved outcomes.

Perioperative outcomes of patients with hypertrophic cardiomyopathy undergoing non-cardiac surgery.

OBJECTIVE: Due to their unique pathophysiological profile, patients with hypertrophic cardiomyopathy (HCM) undergoing non-cardiac surgery require additional attention to perioperative management. We sought to compare perioperative outcomes of patients with HCM undergoing non-cardiac surgery with a matched group patients without HCM. METHODS: This observational cohort study conducted at a tertiary care centre included patients with HCM (n=92, age 67 years, 54% men) undergoing intermediate-risk and high-risk non-cardiac surgeries between 1/2007 and 12/2013 (excluding <18 years, prior septal myectomy/alcohol ablation, low-risk surgery) who were 1:2 matched (based on age, gender, type and time of non-cardiac surgery) with patients without HCM (n=184, median age 65 years, 53% men). A composite endpoint (30-day postoperative death, myocardial infarction, stroke, in-hospital decompensated congestive heart failure (CHF) and rehospitalisation within 30 days) and postoperative atrial fibrillation (AF) were recorded. RESULTS: There was a significantly lower incidence of intraoperative hypotension/tachycardia in patients with HCM versus those without HCM (p<0.001). At 30 days postoperatively, 42 (15%) patients had composite events. Rates of 30-day death, MI or stroke were very low in patients with HCM (5%). However, a significantly higher proportion of patients with HCM met the composite endpoint versus patients without HCM (20 (22%) vs 22 (12%), p=0.03), driven by decompensated CHF. On logistic regression, HCM, high-risk non-cardiac surgery, high anaesthesia risk score and intraoperative duration of hypotension were independently associated with 30-day composite events (p<0.05). CONCLUSIONS: Patients with HCM undergoing high-risk and intermediate-risk non-cardiac surgeries have a low perioperative event rate, at an experienced centre. However, they have a higher risk of composite events versus matched patients without HCM.

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

OBJECTIVES: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy Patients Without Severe Septal Hypertrophy: Implications of Mitral Valve and Papillary Muscle Abnormalities Assessed Using Cardiac Magnetic Resonance and Echocardiography.

BACKGROUND: In patients with hypertrophic cardiomyopathy and left ventricular outflow tract (LVOT) obstruction, but without basal septal hypertrophy, we sought to identify mitral valve (MV) and papillary muscle (PM) abnormalities that predisposed to LVOT obstruction, using echo and cardiac magnetic resonance. METHODS AND RESULTS: We studied 121 patients with hypertrophic cardiomyopathy hypertrophic cardiomyopathy (age, 49±17 years; 60% men; 57% on ß-blockers) with a basal septal thickness of ≤1.8 cm who underwent echocardiography (rest+stress) and cine cardiac magnetic resonance. Echo measurements included maximal LVOT gradient (rest/provocable), MV leaflet length (parasternal long, 4 and 3-chamber views), and abnormal chordal attachment to mid/base of anterior MV. Cine cardiac magnetic resonance measurements included basal septal thickness, number/area of PM heads, and bifid PM mobility (in systole and diastole). Mean basal septal thickness, LVOT gradient, and LV ejection fraction were 1.5±0.3 cm, 72±54 mm Hg, and 61±6%, respectively. The number of anterolateral and posteromedial PM heads was 2.7±0.7 and 2.6±0.7, respectively. Anterolateral and posteromedial PM areas were 19.9±7 cm(2) and 17.1±6 cm(2), respectively. PM mobility was 11±6°. On multivariable analysis, predictors of maximal LVOT gradient were basal septal thickness, bifid PM mobility, anterior mitral leaflet length, and abnormal chordal attachment to base of anterior mitral leaflet. Forty-five patients underwent surgery to relieve LVOT obstruction, of which 52% needed an additional nonmyectomy (MV repair/replacement or PM reorientation) approach. CONCLUSIONS: In hypertrophic cardiomyopathy patients without significant LV hypertrophy, in addition to basal septal thickness, anterior MV length, abnormal chordal attachment, and bifid PM mobility are associated with LVOT obstruction. In such patients, additional procedures on MV and PM (±myectomy) could be considered.

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

BACKGROUND: 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). METHODS: We studied 1,005 HCM patients (50 ± 14 years, 64% men, 77% on ß-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. RESULTS: 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). CONCLUSIONS: 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.

Association of noninvasively measured left ventricular mechanics with in vitro muscle contractile performance: a prospective study in hypertrophic cardiomyopathy patients.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a primary myopathic process in which regional left ventricular dysfunction may exist without overt global left ventricular dysfunction. In obstructive HCM patients who underwent surgical myectomy (SM), we sought to determine if there is a significant association between echocardiographic longitudinal strain, histopathology, and in vitro myocardial performance (resting tension and developed tension) of the surgical specimen. METHODS AND RESULTS: HCM patients (n=122, 54±14 years, 54% men) undergoing SM were prospectively recruited. Longitudinal systolic strain and diastolic strain rates were measured at that basal septum (partially removed at SM) by using velocity vector imaging on preoperative echocardiography. Semiquantitative histopathologic grading of myocyte disarray and fibrosis and in vitro measurements of resting tension and developed tension were made in septal tissue obtained at SM. Mean basal septal systolic strain and diastolic strain rate were -8.3±5% and 0.62±0.4/s, while mild or greater degree of myocyte disarray and interstitial fibrosis were present in 85% and 87%, respectively. Mean resting tension and developed tension were 2.8±1 and 1.4±0.8 g/mm(2). On regression analysis, basal septal systolic strain, diastolic strain rate, disarray, and fibrosis were associated with developed tension (ß=0.19, 0.20, -0.33, and -0.40, respectively, all P<0.01) and resting tension (ß=0.21, 0.22, -0.25, and -0.28, respectively, all P<0.01). CONCLUSION: In obstructive HCM patients who underwent SM, left ventricular mechanics (echocardiographic longitudinal systolic strain and diastolic strain rates), assessed at the basal septum (myocardium removed during myectomy) and histopathologic findings characteristic for HCM (disarray and fibrosis) were significantly associated with in vitro myocardial resting and developed contractile performance.

Association between septal strain rate and histopathology in symptomatic hypertrophic cardiomyopathy patients undergoing septal myectomy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is histopathologically characterized by myocyte hypertrophy, disarray, interstitial fibrosis, and small intramural coronary arteriole dysplasia, which contribute to disease progression. Longitudinal systolic and early diastolic strain rate (SR) measurements by speckle tracking echocardiography are sensitive markers of regional myocardial function. We sought to determine the association between septal SR and histopathologic findings in symptomatic HCM patients who underwent surgical myectomy. METHODS: We studied 171 HCM patients (documented on histopathology) who underwent surgical myectomy to relieve left ventricular outflow tract obstruction. Various clinical and echocardiographic parameters were recorded. Segmental longitudinal systolic and early diastolic SRs (of the septal segment removed at myectomy) were measured from apical 4- and 2-chamber views (VVI 2.0; Siemens, Erlangen, Germany). Histopathologic myocyte hypertrophy, disarray, small intramural coronary arteriole dysplasia, and interstitial fibrosis were classified as none, mild (1%-25%), moderate (26%-50%), and severe (>50%). RESULTS: The mean age was 53 ± 14 years (52% men, ejection fraction 62% ± 5%, mean left ventricular outflow tract gradient 102 ± 39 mm Hg, and basal septal thickness of 2.2 ± 0.5 cm). Mean longitudinal systolic and early diastolic SRs were -0.91 ± 0.5 and 0.82 ± 0.5 (1/s), respectively. There was an inverse association between systolic and early diastolic septal SR and degree of myocyte hypertrophy, disarray, and interstitial fibrosis (all P < .05). There was no association between histopathologic characteristics and other echocardiography parameters. On multivariable regression analysis, myocyte disarray and echocardiographic septal hypertrophy were associated with systolic and early diastolic septal SR (P < .05). CONCLUSION: In HCM patients, there is inverse association between various histopathologic findings and septal SR. Strain rate might potentially provide further insight into HCM pathophysiology.

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

BACKGROUND: We report the predictors of long-term outcomes of symptomatic hypertrophic cardiomyopathy patients undergoing surgical relief of left ventricular outflow tract obstruction. METHODS AND RESULTS: We studied 699 consecutive patients who have hypertrophic cardiomyopathy with severe symptomatic left ventricular outflow tract obstruction (47±11 years, 63% male) intractable to maximal medical therapy, who were referred to a tertiary hospital between January 1997 and December 2007 for the surgical relief of left ventricular outflow tract obstruction. We excluded patients <18 years of age, those with an ejection fraction <50%, those with hypertensive heart disease of the elderly, and those with more than mild aortic or mitral stenosis. Clinical, echocardiographic, and Holter data were recorded. A composite end point of death, appropriate internal cardioverter defibrillator discharges, resuscitated from sudden death, documented stroke, and admission for congestive heart failure was recorded. During a mean follow-up of 6.2±3 years, 86 patients (12%) met the composite end point with 30-day, 1-year, and 2-year event rates of 0.7%, 2.8%, and 4.7%, respectively. The hard event rate (death, defibrillator discharge, and resuscitated from sudden death) at 30 days, 1 year, and 2 years was 0%, 1.5%, and 3%, respectively. Stepwise multivariable analysis identified residual postoperative atrial fibrillation (hazard ratio, 2.12; confidence interval, 1.37-3.34; P=0.001) and increasing age (hazard ratio, 1.49; confidence interval, 1.22-1.82; P=0.001) as independent predictors of long-term composite outcomes. CONCLUSIONS: Symptomatic adult hypertrophic cardiomyopathy patients undergoing surgery for the relief of left ventricular outflow tract obstruction have low event rates during long-term follow-up; worse outcomes are predicted by increasing age and the presence of residual atrial fibrillation during follow-up.

Cardiac magnetic resonance detection of myocardial scarring in hypertrophic cardiomyopathy: correlation with histopathology and prevalence of ventricular tachycardia.

OBJECTIVES: In hypertrophic cardiomyopathy (HCM) patients undergoing surgical myectomy, we sought to determine the association between pre-operative cardiac magnetic resonance (CMR) findings, small intramural coronary arteriole dysplasia (SICAD) on histopathology, and ventricular tachycardia (VT). BACKGROUND: Myocardial scarring (fibrosis) and SICAD are frequently observed on histopathology in HCM patients. CMR measures wall thickness and detects scar. METHODS: Sixty symptomatic HCM patients (62% men; mean age 51 +/- 14 years), with preserved ejection fraction (mean 64 +/- 5%) and no angiographic coronary disease underwent CMR (cine and delayed post-contrast) using a Siemens 1.5 T scanner, followed by septal myectomy. Maximal basal septal thickness was recorded on cine CMR. Scar was determined (percentage of total myocardium) on delayed post-contrast CMR images and quantified as none, mild (0% to 25%), moderate (26% to 50%), or severe (>50%). VT was assessed using Holter monitoring. Degree of SICAD was determined (normal, mild, moderate, and severe) on histopathology of surgical specimen. RESULTS: SICAD and scar were seen in 45 (75%) and 38 (63%) patients, respectively. In 15 patients without SICAD, 12 (80%) had no scar; 23 (70%) patients with mild SICAD had mild scar on CMR. On multivariate analysis, degree of SICAD was independently associated with scar on CMR (Wald chi-square statistic: 6.8, p < 0.01). Patients with basal septal scar on CMR had higher VT frequency compared with those without (27% vs. 5%, p = 0.03). CONCLUSIONS: A strong association exists between degree of SICAD and myocardial scarring seen on CMR.

Abnormally thickened papillary muscle resulting in dynamic left ventricular outflow tract obstruction: an unusual presentation of hypertrophic cardiomyopathy.

We report the case of a symptomatic 18-year-old patient, gene-positive for hypertrophic cardiomyopathy (HCM), who presented with symptomatic dynamic left ventricular outflow tract (LVOT) obstruction caused by an abnormally thickened papillary muscle in the absence of septal hypertrophy. This was confirmed using multimodality imaging, including echocardiography and magnetic resonance imaging. He successfully underwent surgery for papillary muscle realignment without septal myectomy.

Mitral valve abnormalities in hypertrophic cardiomyopathy: echocardiographic features and surgical outcomes.

BACKGROUND: Functional and intrinsic mitral valve (MV) abnormalities are common in hypertrophic cardiomyopathy (HCM); however, morphologic characteristics constituting indications for surgical intervention are incompletely defined. This study was conducted to define the echocardiographic features of MV pathology in patients with HCM and relate these to repairability of the MV, MV procedures performed, durability of repair, and survival. METHODS: From 1986 to 2003, 851 patients with HCM underwent operation, and 115 had a concomitant MV procedure. Detailed analysis of their 784 transthoracic and transesophageal echocardiograms, performed intraoperatively and postoperatively, was conducted. Outcomes were assessed by cross-sectional follow-up. RESULTS: Sixty-seven patients (58%) underwent MV repair, and 48 (42%) had MV replacement. The mean left ventricular outflow tract peak gradient was 70 +/- 50 mm Hg. Systolic anterior motion was present in 95%. Valve abnormalities were degenerative in 36 (31%), myxomatous in 23 (20%), papillary muscle in 23 (20%), restrictive chordal in 22 (19%), restrictive leaflet in 80 (70%), and long leaflet in 64 (56%). Patients undergoing MV repair had higher prevalence of long leaflets and degenerative MV pathology. The anterior mitral leaflet was 3.0 +/- 0.49 cm in the repair group vs 2.5 +/- 0.40 cm in the replacement group (p = 0.0001). MV replacement patients were older, more symptomatic, and had more renal dysfunction and lower hematocrits. By 3 years, 91% of patients with a repair were free of reoperation. CONCLUSIONS: Intrinsic MV pathology is frequently observed in HCM patients with symptomatic obstruction who undergo myectomy. Echocardiography can identify MV features predictive of successful valve repair. Repair, although durable, is feasible in only about half of patients.

Current effectiveness and risks of isolated septal myectomy for hypertrophic obstructive cardiomyopathy.

BACKGROUND: Septal myectomy is the gold-standard therapy for hypertrophic obstructive cardiomyopathy (HOCM). However, it is being challenged by a less-invasive alternative: alcohol septal ablation. This study examined the clinical effectiveness and risks of isolated septal myectomy for HOCM. METHODS: From January 1994 to January 2005, 323 patients underwent isolated septal myectomy (mean age 50 +/- 14 years, 53% male). Preoperative septal thickness was 2.3 +/- 0.46 cm and peak left ventricular outflow tract (LVOT) gradient 68 +/- 43 mm Hg. Effectiveness of myectomy was assessed by echocardiography, sudden death, and functional limitation, early risks by intraoperative and postoperative complications, and late risks by follow-up for HOMC-related reoperation, heart block, and all-cause mortality (mean 3.6 +/- 2.8 years, 1,152 patient-years, 10% followed > or = 8 years). RESULTS: Myectomy was effective, resulting in sustained decrease in septal thickness and LVOT gradient, absence of sudden death, and improved functional status. Early in-hospital morbidity was low, with no hospital deaths; two iatrogenic ventricular septal defects were repaired uneventfully, and 22 pacemakers were required for heart block. In the intermediate term, 10 patients required HOCM-related reoperations (4 redo myectomies, 6 mitral valve procedures), with 92% freedom from reoperation at eight years. Seventy-nine percent were free of pacemakers by 8 years, and survival was 90%, equivalent to that of the general population. CONCLUSIONS: Isolated septal myectomy is effective in eliminating LVOT obstruction and sudden death and in improving functional status, with low operative morbidity and mortality. Few reoperations are required late and outcomes are excellent. It should be considered the treatment of choice for HOCM.

Long-term outcomes in high-risk symptomatic patients with hypertrophic cardiomyopathy undergoing alcohol septal ablation.

OBJECTIVES: We sought to assess outcomes of alcohol septal ablation (ASA) in high-risk patients. BACKGROUND: Because surgical myectomy is the preferred treatment in patients with symptomatic hypertrophic obstructive cardiomyopathy (HOCM) at our institution, we perform ASA in patients who are at high risk for surgery. METHODS: We studied 55 symptomatic HOCM patients (mean age 63 +/- 13 years, 67% women, mean follow-up 8 +/- 1 years), at high risk for surgery (as the result of age/comorbidities) who had ASA between 1997 and 2000. The following were recorded at baseline, 3 months, and 1 year: septal thickness, maximal (resting or provocable) left ventricular outflow tract gradient, Minnesota living with heart failure questionnaire score, and the presence of a permanent pacemaker. All-cause mortality was recorded. RESULTS: No patients died at 48 h, 2 died at 1 year, 7 died at 5 years, and 13 died at 10 years. Only age >65 years at time of ASA predicted long-term mortality (log-rank p = 0.03). Mean maximal left ventricular outflow tract gradient (104 +/- 35 mm Hg vs. 49 +/- 28 mm Hg), septal thickness (2.4 +/- 0.4 cm vs. 1.8 +/- 0.6 cm), and Minnesota living with heart failure score (63 vs. 25) improved at 3 months, compared with baseline (all p < 0.001), with no significant changes at 1 year. New permanent pacemaker was present in 26% of patients. CONCLUSIONS: In symptomatic HOCM patients who are at high risk for surgery, ASA is associated with symptomatic improvement and low short-term mortality; with long-term mortality only associated with older age at time of procedure. In symptomatic HOCM patients at high-risk for surgery, ASA is a viable option.

Selection of hypertrophic cardiomyopathy patients for myectomy or alcohol septal ablation.

This brief review summarizes how patients are selected for myectomy or alcohol septal ablation and what the most results for both are. The most recent literature is reviewed for both septal myectomy and alcohol ablation. The mechanisms for obstruction and mitral regurgitation as well as the indications for both procedures are reviewed. Septal myectomy gives a more consistent relief of the gradient with very low morbidity and mortality. The mortality for alcohol septal ablation is higher than for surgery. In addition, the need for a permanent pacemaker is higher for patients undergoing septal ablation. There maybe an increased risk for ventricular arrhythmia post ablation. Septal myectomy is the gold standard for the invasive treatment of hypertrophic cardiomyopathy. Septal ablation should be considered for the elderly or patients with co-morbid conditions that would make surgery at increased risk.