Risk stratification in hypertrophic cardiomyopathy

Abstract

Sudden cardiac death (SCD) is the most devastating complication of hypertrophic cardiomyopathy (HCM). The greatest challenge in the management of HCM is identifying those at increased risk, since an implantable cardioverter-defibrillator (ICD) is a potentially life-saving therapy. We sought to summarize the available data on SCD in HCM and provide a clinical perspective on the current differing and somewhat conflicting data on risk stratification, with balanced guidance regarding rational clinical decision-making. Additionally, we sought to determine the status of the current implementation of guidelines compiled by HCM experts worldwide. The HCM Risk-SCD model helps improve the risk stratification of HCM patients for primary prevention of SCD by calculating an individual risk estimate that contributes to the clinical decision-making process. Improved risk stratification is important for decision-making before ICD implantation for the primary prevention of SCD.

2020 Clinical practice guidelines for Hypertrophic cardiomyopathy

“…ВСС В основе патогенеза ВСС лежат фатальные нарушения ритма, вызванные ишемией миокарда и электрической нестабильностью. ВСС чаще обусловлена фибрилляцией желудочков (ФЖ) (62,4%), брадиаритмиями (16,5%), желудочковой тахикардией (ЖТ) типа "torsades de pointes" (12,7%), ЖТ (8,3%) и асистолией [79,[110][111][112][113][114][115][116][117][118][119][120][121].…”

Can positron emission tomography help stratify the risk of sudden cardiac death in patients with hypertrophic cardiomyopathy?

“…This is especially relevant as a clinician tries to prevent sudden cardiac death for an individual patient while minimizing the burden of therapy. 6 The only established therapy to prevent sudden cardiac death in patients with HCM is the implantable cardioverter-defibrillator (ICD). [7][8][9] The generally accepted indications for prevention of SCD with an ICD in HCM are based on recognized risk factors, including a prior history of ventricular fibrillation or sustained ventricular tachycardia, maximum LV wall thickness C 30 mm, 10 SCD in a first degree relative with HCM, 11 unexplained syncope within the past 6 months, 12 nonsustained VT (especially if [ 150 bpm), 13 or an abnormal blood pressure response to exercise (failure to increase systolic pressure [ 20 mm Hg).…”

“…[7][8][9] The generally accepted indications for prevention of SCD with an ICD in HCM are based on recognized risk factors, including a prior history of ventricular fibrillation or sustained ventricular tachycardia, maximum LV wall thickness C 30 mm, 10 SCD in a first degree relative with HCM, 11 unexplained syncope within the past 6 months, 12 nonsustained VT (especially if [ 150 bpm), 13 or an abnormal blood pressure response to exercise (failure to increase systolic pressure [ 20 mm Hg). 1,2,6,7,9,11,14 The risk of lethal arrhythmic events is higher for patients presenting with HCM in childhood, 5 those having Troponin I or T mutations, 5 and those with higher serum BNP concentrations. 15 The positive and negative predictive values of any one of these clinical risk factors to predict SCD have been relatively poor.…”

“…15 The positive and negative predictive values of any one of these clinical risk factors to predict SCD have been relatively poor. 5,6 In addition, for continuous variables such as LV wall thickness, the risk of SCD increases in a curvilinear manner, making a clear cut-off value that is ''safe'' all but impossible to establish. 16 Potential clinical features that increase the risk of SCD include younger age (\ 30 years), LV outflow tract obstruction, 17 a remote history of syncope, the presence of epicardial coronary artery disease, end-diastolic LV cavity dimension, 1 left atrial diameter, 12 and the presence of an LV aneurysm.…”

“…17 And yet, despite identification of these clinical features which have been well documented to increase the risk of SCD, even low-risk patients may experience this tragic outcome. 4,6 The prevention of SCD is made more challenging by the fact that living with an ICD can be a significant burden to patients, including the risk of inappropriate shocks, lead malfunction, and requirement for pulse generator replacement. 8 Because of this, any technique that can reduce the need for ICD implantation in patients who are truly at low risk of SCD would be of high clinical value.…”