Introduction
Methods
Study population
Demographic, clinical history data and endpoint definitions
Echocardiographic, Holter monitoring and exercise test data
HCM risk-SCD and ACCF/AHA risk factors
CMR data
Statistical analysis
Results
Overall (n = 493) | No endpoint (n = 470) | Endpoint (n = 23) | p-value | |
---|---|---|---|---|
Age (years) | 46 (33–60) | 47 (33–59) | 37 (27–61) | 0.129 |
Male sex, n (%) | 285 (57.8%) | 274 (58.3%) | 11 (47.8%) | 0.321 |
Clinical history | ||||
Family history of SCD, n (%) | 62 (12.6%) | 59 (12.6%) | 3 (13.0%) | 0.945 |
Unexplained syncope, n (%) | 64 (13.0%) | 61 (13.0%) | 3 (13.0%) | 0.993 |
Known AF, n (%) | 84 (17.0%) | 75 (16.0%) | 9 (39.1%) | 0.004 |
Beta-blockers, n (%) | 364 (73.8%) | 346 (73.6%) | 18 (78.3%) | 0.621 |
Calcium channel blockers, n (%) | 52 (10.5%) | 49 (10.4%) | 3 (13.0%) | 0.690 |
ACEi/ARB, n (%) | 169 (34.3%) | 161 (34.3%) | 8 (34.8%) | 0.959 |
Holter monitoring data | ||||
NSVT, n (%) | 94 (19.1%) | 86 (18.3%) | 8 (34.8%) | 0.049 |
Echocardiography data | ||||
Left atrial size (mm) | 43 (38–47) | 42 (38–47) | 47 (40–52) | 0.025 |
MWT (mm) | 19 (16–23) | 19 (16–23) | 20 (17–26) | 0.213 |
MWT ≥ 30 mm, n (%) | 35 (7.1%) | 31 (6.6%) | 4 (17.4%) | 0.049 |
LVOTO (mm Hg) | 6 (3–50) | 6 (3–50) | 10 (3–48) | 0.472 |
LVOTO ≥ 30 mmHg, n (%) | 174 (35.3%) | 165 (35.1%) | 9 (39.1%) | 0.693 |
Exercise test dataa | ||||
Abnormal BP response, n (%) | 29 (10.2%) | 28 (10.3%) | 1 (9.1%) | 0.897 |
CMR data | ||||
LVEF (%) | 67 (61–70) | 67 (61–70) | 66 (55–70) | 0.259 |
LVEF 35–50%, n (%) | 16 (3.2%) | 13 (2.8%) | 3 (13.0%) | 0.007 |
Indexed EDV (mL/m2) | 73 (62–83) | 73 (62–83) | 76 (63–88) | 0.410 |
Maximum LV thickness (mm) | 21 (17–24) | 21 (17–24) | 23 (17–28) | 0.677 |
LV mass index (g/m2) | 92 (75–114) | 92 (75–114) | 90 (77–120) | 0.600 |
LGE present, n (%) | 391 (79.3%) | 368 (78.3%) | 23 (100%) | 0.012 |
LGE (g) | 5 (0.6–14.2) | 4.6 (0.6–13.8) | 26.3 (12.7–36.8) | < 0.001 |
LGE (%) | 2.9 (0.4–8.4) | 2.7 (0.3–7.7) | 12.0 (9.3–24.3) | < 0.001 |
Agreement between risk stratification tools
Outcomes
Overall (n = 493) | No endpoint (n = 470) | Endpoint (n = 23) | p-value | |
---|---|---|---|---|
HCM Risk-SCD | 0.018 | |||
Low risk, n (%) | 362 (73.4%) | 351 (74.7%) | 11 (47.8%) | – |
Intermediate risk, n (%) | 66 (13.4%) | 59 (12.6%) | 7 (30.4%) | – |
High risk, n (%) | 65 (13.2%) | 60 (12.8%) | 5 (21.7%) | – |
Risk at 5-years (%) | 2.5 (1.7–4.1) | 2.4 (1.7–4.0) | 4.2 (2.4–6.0) | 0.003 |
ACCF/AHA | 0.075 | |||
ICD not recommended, n (%) | 281 (57.0%) | 273 (58.1%) | 8 (34.8%) | – |
ICD can be useful, n (%) | 68 (13.8%) | 62 (13.2%) | 6 (26.1%) | – |
ICD reasonable, n (%) | 144 (29.2%) | 135 (28.7%) | 9 (39.1%) | – |
LGE classification | < 0.001 | |||
0%, n (%) | 102 (20.7%) | 102 (21.7%) | 0 (0%) | – |
0.1–10.0%, n (%) | 285 (57.8%) | 279 (59.4%) | 6 (26.1%) | – |
10.1–19.9%, n (%) | 63 (12.8%) | 55 (11.7%) | 8 (34.8%) | – |
≥ 20%, n (%) | 43 (8.7%) | 34 (7.2%) | 9 (39.1%) | – |
Role of LGE% in risk stratification
Univariate analysis | Multivariate analysis | ||||
---|---|---|---|---|---|
HR (95% CI) | p-value | Model | HR (95% CI) | p-value | |
Age | 0.996 (0.970–1.023) | 0.783 | Base model | ||
Male | 0.638 (0.281–1.446) | 0.282 | LGE% | 1.081 (1.044–1.120) | < 0.001 |
Known AF | 3.299 (1.425–7.637) | 0.005 | Known AF | 2.421 (0.903–6.490) | 0.079 |
Unexplained syncope | 0.926 (0.274–3.131) | 0.901 | LVEF | 1.006 (0.951–1.064) | 0.844 |
Family history of SCD | 0.711 (0.236–2.682) | 0.711 | Left atrial size | 1.036 (0.974–1.102) | 0.259 |
NSVT | 2.134 (0.903–5.042) | 0.084 | NSVT | 1.121 (0.441–2.848) | 0.810 |
Left atrial size | 1.060 (1.016–1.105) | 0.007 | With HCM Risk-SCD | ||
LVOTO | 1.004 (0.992–1.015) | 0.516 | HCM Risk-SCD | 0.970 (0.866–1.086) | 0.596 |
LVM > 30 mm | 1.194 (0.516–2.763) | 0.679 | LGE% | 1.087 (1.053–1.123) | < 0.001 |
LVMi | 1.003 (0.995–1.011) | 0.478 | With ACCF/AHA | ||
LVEF | 0.951 (0.903–1.002) | 0.057 | ‘ICD not recommended’ | reference | – |
LGE% | 1.083 (1.052–1.116) | < 0.001 | ‘ICD can be useful’ | 1.971 (0.664–5.847) | 0.221 |
HCM Risk-SCD | 1.034 (0.944–1.132) | 0.476 | ‘ICD reasonable’ | 0.966 (0.354–2.636) | 0.946 |
ACCF/AHA | LGE% | 1.082 (1.049–1.117) | < 0.001 | ||
‘ICD not recommended’ | reference | – | |||
‘ICD can be useful’ | 3.053 (1.058–8.809) | 0.039 | |||
‘ICD reasonable’ | 1.698 (0.652–4.422) | 0.278 |
LGE | ||||
---|---|---|---|---|
≤ 10% | 10.1–19.9% | ≥ 20% | ||
ACCF/AHA algorithm | ||||
No events | ICD not recommended | 241 | 21 | 11 |
ICD can be useful | 47 | 12 | 3 | |
ICD reasonable | 93 | 22 | 20 | |
Events | ICD not recommended | 2 | 4 | 2 |
ICD can be useful | 2 | 1 | 3 | |
ICD reasonable | 2 | 3 | 4 | |
Non-event NRI: 127/470 (0.27) | ||||
Event NRI: 2/23 (0.09) | ||||
Overall NRI: 0.36 (p = 0.021) | ||||
HCM Risk-SCD | ||||
No events | Low risk | 298 | 32 | 21 |
Intermediate risk | 44 | 12 | 3 | |
High risk | 39 | 11 | 10 | |
Events | Low risk | 2 | 5 | 4 |
Intermediate risk | 1 | 2 | 4 | |
High risk | 3 | 1 | 1 | |
Non-event NRI: 38/470 (0.08) | ||||
Event NRI: 8/23 (0.35) | ||||
Overall NRI: 0.43 (p = 0.011) |