Table 1. Baseline clinical and imaging demographics, and postoperative outcomes in 482 obstructive HCM patients undergoing surgical myectomy.
| Characteristic | Value (n=482) |
|---|---|
| Demographics | |
| Male | 273 (56.6) |
| Age at myectomy (years) | 52.1±14.3 |
| Age <30 years at time of surgery | 42 (8.7) |
| Age ≥60 years at time of surgery | 151 (31.3) |
| Transthoracic echocardiography | |
| LVOT resting gradient (mmHg) | 56.4±42.4 |
| LVOT resting gradient 30–49 mmHg | 53 (11.3) |
| LVOT resting gradient ≥50 mmHg | 282 (60.0) |
| Maximum LV thickness (mm) | 20.1±4.7 |
| Maximum LV thickness ≤15 mm | 50 (10.7) |
| Maximum LV thickness ≥30 mm | 22 (4.7) |
| LV ejection fraction (%) | 65.6±4.0 |
| Left atrial dimension (mm) | 42.9±7.3 |
| LVED (mm) | 40.5±5.8 |
| Contrast-CMR | |
| CMR studies | 302 (63.2) |
| Presence of LGE | 183 (66.3) |
| Risk Factors | |
| Family history of HCM | 114 (24.3) |
| Family history HCM-related sudden death | 41 (8.6) |
| NSVT on Holter monitor | 43 (9.0) |
| History of Syncope | 70 (14.6) |
| NYHA functional classification | |
| I | 2 (0.4) |
| II | 7 (1.5) |
| III | 469 (97.3) |
| IV | 4 (0.8) |
| Preoperative comorbidities and interventions | |
| Atrial fibrillation | 180 (37.5) |
| Paroxysmal | 166 (34.4) |
| Permanent/persistent | 14 (2.9) |
| Previous alcohol septal ablations | 12 (2.5) |
| Previous ICD implantation | 84 (17.4) |
| Appropriate ICD interventions | 12 (14.3) |
| Resuscitated cardiac arrest | 2 (0.4) |
| Drug therapy | |
| Beta-blockers | 337 (70.4) |
| Calcium channel blockers | 172 (35.9) |
| Disopyramide | 32 (6.7) |
| Amiodarone | 13 (2.7) |
| ACE inhibitor/ARB | 72 (15.0) |
| Diuretics | 88 (18.4) |
| Anticoagulants | 47 (9.8) |
| Warfarin | 39 (8.1) |
| Novel oral anticoagulants | 8 (1.7) |
| Genetic testing | |
| MYBPC3 | 14 (2.9) |
| MYH7 | 5 (1.0) |
| TNNT2 | 2 (0.4) |
| MYHC | 1 (0.2) |
| MYHC7 + MYBPC | 1 (0.2) |
| Operative details and concomitant procedures | |
| Isolated myectomy | 347 (72.0) |
| Cox-maze procedure | 83 (17.2) |
| Coronary artery bypass grafting | 30 (6.2) |
| Mitral annuloplasty | 21 (4.4) |
| Mitral valve replacement | 1 (0.2) |
| Subaortic membrane resection | 10 (2.1) |
| Aortic valve repair or replacement | 5 (1.0) |
| Other procedures | 15 (3.1) |
| Need for repeat cardiopulmonary bypass run | 52 (10.8) |
| Perioperative events | |
| Atrial fibrillation | 101 (21.0) |
| Complete heart block | 19 (4.0)* |
| Stroke | 4 (0.8) |
| Ventricular septal defect | 5 (1.0) |
| Renal failure requiring hemodialysis | 1 (0.2) |
| 30-day operative mortality | 4 (0.8) |
| Postoperative length of stay (d) | 6.2±3.1 |
Data are shown as n (%) or mean ± SD. *, excludes patient with predisposing conditions or adjunctive surgical interventions judged to increase risk for complete heart block. LVOT, left ventricular outflow gradient; LV, left ventricle; LVED, left ventricle at end diastole; CMR, cardiac magnetic resonance; LGE, late gadolinium enhancement; NSVT, non-sustained ventricular tachycardia; NYHA, New York Heart Association; ICD, implantable cardioverter defibrillator; ACE, angiotensin-converting enzyme; ARB, angiotensin II receptor blocker; MYBPC3, myosin-binding protein C; MYH7, myosin heavy chain 7; TNNT, troponin T; MYHC, myosin heavy chain.