Abstract 20544: Family History Characteristics as Risk Factors for Sudden Cardiac Death Events in Hypertrophic Cardiomyopathy
Introduction: Sudden cardiac death (SCD) is a tragic outcome of hypertrophic cardiomyopathy (HCM). Risk stratification criteria to determine who would most benefit from implantable cardioverter defibrillator (ICD) therapy are imprecise. Family history of SCD in a 1st-degree relative is a known SCD risk factor (RF). This study sought to investigate family history characteristics as potential SCD RF.
HYPOTHESIS: Those with a family history of: (1) SCD in 2nd-degree or more distant relative, and (2) resuscitated cardiac arrest or appropriate ICD therapy may also be at increased risk.
METHODS: Patients attending 2 major HCM centres and definite diagnosis of HCM were included. Primary outcome was first SCD event (i.e. SCD, resuscitated cardiac arrest, and appropriate ICD therapy). Traditional RF included family history of SCD, severe LV wall thickness (LVWT; ≥30mm), unexplained syncope and non-sustained VT. Data were collected at earliest time point available and outcome assessed at most recent follow-up. Logistic regression analysis was performed.
RESULTS: 898 HCM patients were identified (766 probands, 132 affected relatives); mean age 53±18 years, 559 [62%] males, and mean LVWT 21±6mm). Over mean follow-up time of 4.5±4.6 years (total 3954 patient years) 60 SCD events were recorded (14 SCD, 16 resuscitated cardiac arrest, 30 appropriate ICD discharge). Compared to patients with no traditional RF (17%), ≥2 traditional RF was associated with a SCD event (OR 4.0, 95%CI 1.9-8.2, p<0.0001), while 1 RF (34%) was not significant (OR 1.8, 95%CI 0.9-3.6, p=ns). 29% of SCD events occurred with no traditional RF. 43% had a family history of SCD of a 2nd-degree (or more distant) relative, and there was no difference compared to SCD of a 1st-degree relative (OR 0.7, 95%CI 0.3-1.8, p=ns). Family history of resuscitated cardiac arrest or appropriate ICD discharge was not independently associated with increased risk of SCD events after adjusting for family history of SCD (adjusted OR 2.0, 95%CI 0.9-4.8, p=ns).
CONCLUSIONS: Traditional RF remain a strong predictor of SCD events. SCD of a 2nd-degree (or more distant) relatives was the same as SCD of a 1st-degree relative. Current guidelines, which only recognise family history of SCD in a 1st-degree relative, may need to be modified
Author Disclosures: J. Ingles: None. C. Burns: None. C. Medi: None. L. Yeates: None. L. McCormack: None. L. Hunt: None. J. McGaughran: None. J. Atherton: None. C. Semsarian: None.
- © 2014 by American Heart Association, Inc.