Obesity and sudden cardiac death in the young: Clinical and pathological insights from a large national registry

Abstract

Aims Obesity is an increasing public health problem and a risk factor for cardiovascular diseases. The aim of the study was to determine the main features and aetiologies in a large cohort of sudden cardiac deaths that occurred in obese subjects. Methods Between 1994 and 2014, 3684 consecutive cases of unexpected sudden cardiac death were referred to our cardiac pathology centre. This study was confined to young individuals (age ≤ 35 years) for whom information about body mass index was available and consisted of 1033 cases. Results Two-hundred and twelve individuals (20%) were obese. In obese sudden cardiac death victims the main post-mortem findings were: normal heart (sudden arrhythmic death syndrome) ( n = 108; 50%), unexplained left ventricular hypertrophy ( n = 25; 12%) and critical coronary artery disease ( n = 25; 12%). Less common were hypertrophic cardiomyopathy ( n = 4; 2%) and arrhythmogenic right ventricular cardiomyopathy ( n = 4;2%). When compared with non-obese sudden cardiac death victims, sudden arrhythmic death syndrome was less common (50% vs. 60%, P < 0.01), whereas left ventricular hypertrophy and critical coronary artery disease were more frequent (12% vs. 2%, P < 0.001 and 12% vs. 3%, P < 0.001, respectively). The prevalence of critical and non-critical coronary artery disease was significantly higher in obese individuals (23% vs. 10% in non-obese individuals, P < 0.001). Conclusions Various conditions underlie sudden cardiac death in obesity, with a prevalence of sudden arrhythmic death syndrome, left ventricular hypertrophy and coronary artery disease. The degree of left ventricular hypertrophy measured by heart weight is excessive even after correction for body size. Almost one in four young obese sudden death patients show some degree of coronary artery disease, underscoring the need for primary prevention in this particular subgroup.

Relation of Body Mass Index Categories with Risk of Sudden Cardiac Death

“…40) Left ventricular hypertrophy is a common finding in overweight or obese patients and is associated with an increased risk of SCD. 41) The hearts of obese individuals display pathological myocardial changes including myocyte hypertrophy, fibrosis, focal myocardial disarray, fatty and mononuclear cell infiltration, and increased epicardial fat. 42) Substantial evidence supports an increased electrical irritability in obesity.…”

Obese cardiogenic arrest survivors with significant coronary artery disease had worse in-hospital mortality and neurological outcomes

“…Cardiogenic arrest may be caused by CAD, acute myocardial infarction, heart failure, cardiac tamponade, or fatal arrhythmia 5 , 6 , which have been reported to be attributed to obesity. Obesity was also reported to increase the risk of sudden arrhythmic death syndrome and left ventricular hypertrophy 7 . Compared with the normal-weight population, obese men and women have a 2.6- and 5.8-fold higher risk of SCA, respectively 8 .…”

Obesity as a modifiable risk factor for hypertrophic cardiomyopathy

“…Microscopic criteria discriminated between idiopathic LVH and HCM by the absence or presence of myocyte disarray. 10 Data describing the risk of developing clinical HCM amongst obese individuals are lacking. Olivotto et al 11 reported that obesity was highly prevalent amongst 275 HCM patients and that obesity was independently associated with increased LV mass.…”