Table 1.
Subject characteristics
| Overall | Index patient | Family member | p-value | ||
|---|---|---|---|---|---|
| (n = 250) | (n = 97) | (n = 153) | |||
| Demographics | |||||
| Age at inclusion (years) | 54.9 [43.3, 66.6] | 55.5 [47.3, 67.2] | 53.7 [40.5, 64.5] | 0.183 | |
| Male sex | 137 (54.8) | 64 (66.0) | 73 (47.7) | 0.007 | |
| Body surface area (m2) | 1.96 [1.83, 2.13] | 1.95 [1.85, 2.19] | 1.96 [1.82, 2.10] | 0.448 | |
| Genetics | |||||
| MYBPC3 variant | c.2373dupG | 185 (74.0) | 69 (71.1) | 116 (75.8) | 0.500 |
| c.2827C > T | 30 (12.0) | 14 (14.4) | 16 (10.5) | 0.425 | |
| c.2864_2865delCT | 15 (6.0) | 5 (5.2) | 10 (6.5) | 0.788 | |
| c.3776delA | 20 (8.0) | 9 (9.3) | 11 (7.2) | 0.634 | |
| Patient history | |||||
| Syncope | 28 (11.8) | 15 (16.1) | 13 (9.0) | 0.103 | |
| NYHA class | I/II | 144 (93.5) | 52 (88.1) | 92 (96.8) | 0.045 |
| III/IV | 10 (6.5) | 7 (11.9) | 3 (3.2) | ||
| Family history of sudden cardiac death | Any first-degree family member | 86 (36.0) | 0.489 | ||
| In accordance with ESC HCM Risk-SCD calculator | 45 (22.1) | 0.300 | |||
| Holter monitoring | |||||
| Non-sustained ventricular tachycardia | 102 (57.0) | 51 (65.4) | 51 (50.5) | 0.050 | |
| Imaging | |||||
| Maximum wall thickness (mm) | 16 [12, 20] | 19 [17, 23] | 13 [10, 17] | <0.001 | |
| Maximum LV outflow tract gradient (mm Hg) | 6 [4, 10] | 8 [5, 15] | 5 [4, 7] | 0.003 | |
| LV end-diastolic diameter (mm) | 46 [40, 50] | 45 [40, 49] | 46 [41, 50] | 0.438 | |
| LV ejection fraction (%) | 60 [55, 62] | 60 [52, 62] | 60 [55, 63] | 0.232 | |
| LV diastolic dysfunction | Normal | 69 (59.5) | 13 (36.1) | 56 (70.0) | <0.001 |
| Impaired relaxation | 29 (25.0) | 10 (27.8) | 19 (23.8) | ||
| Pseudonormalisation | 11 (9.5) | 9 (25.0) | 2 (2.5) | ||
| Restrictive | 7 (6.0) | 4 (11.1) | 3 (3.8) | ||
| LA diameter (mm) | 41 [36, 46] | 42 [37, 46] | 39 [36, 46] | 0.533 | |
| Outcomes at inclusion | |||||
| Phenotype | Phenotype-negative | 59 (25.4) | 3 (3.2)a | 56 (40.6) | <0.001 |
| HCM 13–14 mm | 18 (7.8) | 1 (1.1) | 17 (12.3) | ||
| HCM ≥ 15 mm | 151 (65.1) | 88 (93.6) | 63 (45.7) | ||
| DCM | 4 (1.7) | 2 (2.1) | 2 (1.4) | ||
| Primary outcome | Composite endpoint | 115 (50.2) | 71 (78.0) | 44 (31.7) | <0.001 |
| Maximum wall thickness ≥ 20 mm | 88 (39.8) | 58 (65.9) | 30 (22.4) | <0.001 | |
| Septal reduction therapy | 17 (7.8) | 14 (16.1) | 3 (2.3) | <0.001 | |
| Malignant ventricular arrhythmia | 21 (9.3) | 14 (15.4) | 7 (5.1) | 0.011 | |
| Heart failure | 47 (22.0) | 30 (34.9) | 17 (13.2) | <0.001 | |
| Congestive heart failure | 28 (13.6) | 17 (21.8) | 11 (8.5) | 0.011 | |
| Systolic heart failure | 33 (16.0) | 20 (26.3) | 13 (9.9) | 0.003 |
NYHA New York Heart Association, ESC European Society of Cardiology, SCD sudden cardiac death, LV left ventricular, LA left atrial, HCM hypertrophic cardiomyopathy, DCM dilated cardiomyopathy
Continuous data are shown as means ± standard deviation for normally distributed variables or median [interquartile range] for non-normally distributed variables. Dichotomous and categorical data are shown as counts (% of valid). p-values < 0.05 are depicted in bold
aIncidental finding in one subject and genetic testing prompted by a sudden cardiac death of a family member in two subjects