Prevalence of major risk factors
| Risk factors profile* | n (%) |
|---|---|
| FHSCD | 481 (30%) |
| NSVT | 297 (18%) |
| Unexplained syncope | 276 (17%) |
| ABPRE* | 158 (24%) |
| Severe LVH | 116 (7%) |
| 0 risk factor | 660 (41%) |
| 1 risk factor | 636 (40%) |
| 2 risk factors | 249 (15%) |
| 3 risk factors | 51 (3%) |
| 4 risk factors | 9 (0.6%) |
| 5 risk factors† | 1 (0.06%) |
*Of the 664 patients aged ≤40 years, 519 (78%) had a complete risk factor dataset. Missing data were present in three of the five risk factors: Holter monitoring was unavailable in 88 patients (13%), a recorded history of unexplained syncope in 15 (2.3%) and an exercise test in 96 patients (14%). Of the 942 patients aged >40 years, 769 (82%) had a complete risk factor dataset (ABPRE not included). In this group, missing data involved two risk factors: Holter monitoring was not available in 157 patients (17%) and a recorded history of unexplained syncope in 44 (5%).
†In the subsequent analysis, the single patient with five risk factors was grouped with those with four risk factors.
ABPRE, abnormal blood pressure response to exercise; FHSCD, family history of sudden cardiac death; LVH, left ventricular hypertrophy; NSVT, non-sustained ventricular tachycardia.