Table 1.
Demographic variables study cohort
| Total | QTc ≤ 480 ms | QTc > 480 ms | P-value* | |
|---|---|---|---|---|
| n | 479 | 417 | 62 | — |
| Sex (male/female) | 278/201 | 244/173 | 34/28 | 0.58 |
| Age at diagnosis (years) | 41.1 ± 18 | 41.1 ± 18 | 41.1 ± 18 | 0.98 |
| Mean NYHA class at diagnosis | 1.9 ± 0.8 | 1.9 ± 0.8 | 2.4 ± 0.8 | 0.001 |
| MLVWT (mm) | 22.1 ± 6 | 21.8 ± 6 | 24.1 ± 8 | 0.03 |
| LVOT gradient (mm Hg) | 40.7 ± 40 | 38.9 ± 41 | 52.6 ± 37 | 0.01 |
| Patients w/obstruction, n (%) | 233 (49) | 188 (45) | 45 (74) | <0.0001 |
| QTc (ms) | 440.7 ± 37 | 431.1 ± 28 | 505.3 ± 25 | <0.0001 |
| JTc (ms) | 327.6 ± 37 | 323.3 ± 33 | 357.0 ± 46 | <0.0001 |
| QRS (ms) | 108.6 ± 27 | 104.3 ± 22 | 137.8 ± 39 | <0.0001 |
| Family Hx of HCM, n (%) | 146 (31) | 127 (31) | 19 (31) | 1 |
| Family Hx of sudden death, n (%) | 82 (17) | 71 (17) | 11 (18) | 0.85 |
| Surgical myectomy, n (%) | 141 (29) | 117 (28) | 24 (39) | 0.12 |
| Septal ablation, n (%) | 31 (6) | 23 (6) | 8 (13) | 0.05 |
| Myectomy or ablation, n (%) | 172 (36) | 140 (34) | 32 (52) | 0.01 |
| ICD, n (%) | 90 (19) | 72 (17) | 18 (29) | 0.04 |
| Genotype positive, n (%) | 224 (47) | 201 (48) | 23 (37) | 0.13 |
| Mutation location, n (%) | ||||
| MYBPC3 | 86 (18) | 77 (18) | 9 (15) | 0.56 |
| MYH7 | 80 (17) | 72 (17) | 8 (13) | 0.5 |
| Thin filament | 18 (4) | 17 (4) | 1 (2) | 0.55 |
| Z-disc | 12 (3) | 10 (2) | 2 (3) | 1 |
| Multiple | 28 (6) | 25 (6) | 3 (5) | 0.94 |
Shown are the total demographics for the complete study cohort as well as a comparison between patients with a QTc ≤ 480 ms and a QTc > 480 ms. All values expressed at mean ± SD. Of note, Z-disc genes were not studied in the Florence cohort.
*P-value compares the difference between cohorts with a QTc ≤ 480 and QTc > 480 ms.