Table 1.
Clinical baseline characteristics
| Characteristic | ICM group (n = 25) | Control group (n = 25) | p value |
|---|---|---|---|
| Age, years | 51±16 | 52±16 | 0.94 |
| Sex, male | 18 (72%) | 18 (72%) | 1.00 |
| NYHA functional class ≥II | 7 (28%) | 7 (28%) | 1.00 |
| History of myectomy | 2 (8%) | 3 (12%) | 0.64 |
| Left ventricular systolic function | |||
| Normal (EF ≥50%) | 25 (100%) | 24 (96%) | 1.00 |
| Mildly impaired (EF 45–49%) | 0 | 1 (4%) | |
| Genetic testing | 21 (84%) | 23 (92%) | 0.67 |
| Pathogenic mutation | 12 (48%) | 14 (56%) | 0.57 |
| MYBPC3 | 8 (32%) | 11 (44%) | 0.38 |
| MYH7 | 3 (12%) | 1 (4%) | 0.30 |
| TPM1 | 1 (4%) | 0 | 1.00 |
| TNNI3 | 0 | 2 (8%) | 0.49 |
| History of NSVT | 13 (52%) | 8 (32%) | 0.15 |
| History of unexplained syncope | 8 (32%) | 1 (4%) | 0.01 |
| Peak LVOT gradient | 6 (5–17) | 12 (6–82) | 0.19 |
| Family history of SCD | 3 (12%) | 3 (12%) | 1.00 |
| Left atrial size | 43±9 | 45±7 | 0.23 |
| Maximum left ventricular wall thickness | 18±5 | 18±5 | 0.49 |
| HCM Risk-SCD score | 3.41±1.31 | 3.31±1.43 | 0.79 |
| <4% | 13 (52%) | 13 (52%) | 1.00 |
| ≥4 to ≤6% | 12 (48%) | 12 (48%) | 1.00 |
| Electrocardiography | 25 (100%) | 25 (100%) | 1.00 |
| Sinus rhythm | 24 (96%) | 25 (100%) | 1.00 |
| AF | 1 (4%) | 0 | 1.00 |
| PR interval, if sinus rhythm | 164±25 | 182±25 | 0.85 |
| QRS duration, ms | 105±18 | 102±28 | 0.56 |
| QTc duration, ms | 426±25 | 416±28 | 0.61 |
| Holter monitoring | 25 (100%) | 25 (100%) | 1.00 |
| <1% PVCs | 23 (92%) | 25 (100%) | 0.49 |
| 1–10% PVCs | 2 (8%) | 0 | 0.49 |
| NSVT | 11 (44%) | 6 (24%) | 0.14 |
| SVT | 7 (28%) | 12 (48%) | 0.15 |
| AF | 2 (8%) | 0 | 0.49 |
| Cardiac medication | 16 (64%) | 19 (76%) | 0.35 |
| Beta blocker | 12 (48%) | 14 (56%) | 0.57 |
| Loop diuretics | 5 (20%) | 0 | 0.05 |
| ACE-inhibitor/ARB | 6 (24%) | 3 (12%) | 0.27 |
| Oral anticoagulants | 5 (20%) | 5 (20%) | 1.00 |
| Calcium channel blocker | 3 (16%) | 4 (16%) | 0.68 |
| Amiodarone/sotalol | 2 (8%) | 2 (8%) | 1.00 |
Data are presented as n (%), mean ± SD, or median with IQR. ACE, angiotensin converting enzyme; ARB, angiotensin receptor blocker; CAD, coronary artery disease; EF, ejection fraction; HCM, hypertrophic cardiomyopathy; LVOT, left ventricular outflow tract; NSVT, nonsustained ventricular tachycardia; NYHA, New York Heart Association; PVC, premature ventricular complex; SCD, sudden cardiac death; IQR, interquartile range; SVT, supraventricular tachycardia; AF, atrial fibrillation.