Table 1.
Baseline Characteristics of Study Sample
| Variable |
Total N=2268 |
Earlier Surgery N=950 |
Class I Indication N=1318 |
|---|---|---|---|
| Age, y | 56±14 | 55±14 | 56±12 |
| Male sex | 1246 (55%) | 541 (57%) | 705 (54%) |
| Body‐surface area, m2 | 2.0±0.2 | 2.0±0.3 | 2.0±0.2 |
| Hypertension | 817 (36%) | 333 (35%) | 487 (37%) |
| Diabetes mellitus | 278 (12%) | 124 (13%) | 154 (12%) |
| Smoking history | 598 (26%) | 241 (26%) | 351 (27%) |
| Obstructive CAD | 222 (10%) | 85 (9%) | 134 (10%) |
| Family history of HCM | 408 (18%) | 162 (17%) | 246 (18%) |
| Family history of SCD | 227 (10%) | 95 (10%) | 132 (10%) |
| History SCD | 25 (1.1%) | 11 (1.2%) | 14 (1.1%) |
| History of NSVT | 223 (10%) | 93 (10%) | 130 (10%) |
| History of syncope | 295 (13%) |
76 (8%) None exertional |
219 (17%) All exertional |
| History of atrial fibrillation | 535 (24%) | 228 (24%) | 307 (23%) |
| History of stroke | 91 (4%) | 38 (4%) | 53 (4%) |
| History of prior alcohol septal ablation | 18 (0.8%) | 0 | 18 (1%) |
| Implantable defibrillator | 287 (13%) | 114 (12%) | 173 (13%) |
| Permanent pacemaker | 60 (3%) | 29 (3%) | 31 (2%) |
| β‐Blockers | 1769 (78%) | 684 (72%) | 1085 (82%) |
| Calcium channel blocker | 635 (28%) | 247 (26%) | 388 (29%) |
| Disopyramide | 91 (4%) | 38 (4%) | 53 (4%) |
| Angina | 431 (19%) | 114 (12%) | 317 (24%) |
| NYHA class | |||
| I | 209 (9%) | 209* (22%) | 0 |
| II | 1005 (44%) | 741 (78%) | 264 (20%) † |
| ≥III | 1054 (46%) | 0 | 1054 (80%) |
| ESC % 5‐y SCD risk score | 3.7±2 | 3.7±2 | 3.7±2 |
| ESC % 5‐y SCD risk categories | |||
| Low risk (<4%) | 1369 (60%) | 555 (58%) | 814 (62%) |
| Intermediate (4–6%) | 702 (31%) | 306 (32%) | 396 (30%) |
| High (>6%) | 197 (9%) | 89 (9%) | 108 (8%) |
CAD indicates coronary artery disease; ESC, European Society of Cardiology; HCM, hypertrophic cardiomyopathy; LVOT, left ventricular outflow tract; NSVT, nonsustained ventricular tachycardia; NYHA, New York Heart Association; and SCD, sudden cardiac death.
*
All patients deemed to be in NYHA class I at baseline had symptomatic impairment of exercise capacity on stress echocardiography along with severe LVOT obstruction.
†
All patients in this subgroup also had intractable angina or exertional syncope on maximally tolerated medical therapy.