Independent Assessment of the European Society of Cardiology Sudden Death Risk Model for Hypertrophic Cardiomyopathy

doi:10.1016/j.amjcard.2015.05.047

The American Journal of Cardiology

Volume 116, Issue 5, 1 September 2015, Pages 757-764

https://doi.org/10.1016/j.amjcard.2015.05.047 Get rights and content

Risk stratification for sudden death (SD) is an essential component of hypertrophic cardiomyopathy (HC) management, given the proven effectiveness of implantable cardioverter-defibrillators (ICD) for preventing SD. Although highly effective in identifying high-risk patients, current stratification algorithms remain incomplete and novel strategies are encouraged. In this regard, reliability of the statistical model to predict SD risk in HC, as recommended by the recent European Society of Cardiology (ESC) guidelines, was retrospectively tested in an independent cohort of 1,629 consecutive patients with HC aged ≥16 years. Of the 1,629 patients, 35 incurred SD events, but only 4 of these (11%) had high predictive risk scores >6%/5 years consistent with an ICD recommendation, and most (60%; n = 21) had scores <4%/5 years that would not justify ICDs. Of 46 high-risk patients with appropriate ICD interventions for ventricular fibrillation/tachycardia, 27 (59%) had low SD risk scores of <4%/5 years, regarded by ESC as insufficient to recommend ICDs, and only 12 (26%) had scores >6%/5 years, considered an ICD indication; 11 of these 12 had already met conventional criteria warranting implantation with 2 to 3 risk markers. Of 414 patients with ICDs but without appropriate interventions, 258 (62%) had low risk scores (<4%/5 years) that would argue against implant. In conclusion, primary risk stratification using the ESC prognostic score applied retrospectively to a large independent HC cohort proved unreliable for prediction of future SD events. Most patients with HC with SD or appropriate ICD interventions were misclassified with low risk scores and therefore would have remained unprotected from arrhythmic SD without ICDs.

Section snippets

Methods

Case records of the Hypertrophic Cardiomyopathy Centers of the Minneapolis Heart Institute Foundation and Tufts Medical Center were accessed, and 1,629 consecutively evaluated and prospectively followed patients with HC aged ≥16 years at the first evaluation (October 1992 to May 2014) were identified, with a total follow-up period of 13,274 patient-years, to November 2014. This project was reviewed and approved by the institutional review boards at each center.

The study population of 1,629

Results

Of the 1,629 total study patients, at initial evaluation, 901 (55%) were asymptomatic (New York Heart Association class I), 443 (27%) were mildly symptomatic (class II), and 285 (17%) were severely symptomatic (classes III/IV); 1,067 (66%) patients were men. Echocardiographic measurements were: maximum LV wall thickness (usually ventricular septum), 21 ± 6 mm with 135 patients (8%) ≥30 mm; LV end-diastolic dimension, 34 ± 5 mm; left atrial dimension, 42 ± 8 mm; ejection fraction, 64 ± 7%.

In 35

Discussion

With the ICD widely available to patients with HC over the past 15 years, the principle of SD prevention has become a reality.1, 2, 3, 9, 10, 11, 12, 13, 14, 15, 17 The risk stratification algorithm in general usage, based on retrospective cohort analyses, has been highly effective for identifying many patients with HC who will benefit from ICD therapy, instrumental in decreasing SD rate1, 9, 10, 11, 13, 28 and HC-related mortality to 0.5%/year.²⁸

It is also apparent that the current risk

Disclosures

The authors have no conflicts of interest to disclose.

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How are the predictors of sudden death modified after septal myectomy surgery?
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Hypertrophic cardiomyopathy is a condition associated with an increased risk of sudden death compared to the general population. Extended septal myectomy surgery has been suggested to impact the reduction of sudden death events according to various publications. The aim of this study was to assess changes in the prevalence of sudden death predictors in a population of patients undergoing extended septal myectomy surgery.
Ninety-four consecutive patients underwent extended septal myectomy surgery due to symptomatic hypertrophic cardiomyopathy. Risk factors for sudden death, as defined by the American Heart Association and the European Society of Cardiology, were evaluated before and three months after surgery.
The mean age of the population was 57 ± 13 years. A significant reduction was observed in the maximum septal thickness from 21.3 to 14 mm (p<0.001), along with a decrease in the anteroposterior diameter of the left atrium from 51 to 47 mm (p=0.021). Resting intraventricular gradients decreased from 49.2 to 6.4 mmHg (p<0.001), and Valsalva-induced gradients decreased from 93.9 to 8.7 mmHg (p<0.001). Non-sustained ventricular tachycardia decreased from 6% to 2% (p<0.001), and atrial fibrillation decreased from 30% to 15% (p<0.001). Ischemic behavior during exercise stress echo decreased from 6% to 0%, and the European Society of Cardiology sudden death risk score reduced from 3.32 to 1.44 (p<0.001).
In this cohort of hypertrophic cardiomyopathy patients, extended septal myectomy surgery was associated with a reduction in the number and magnitude of sudden death predictors, potentially explaining the reduced mortality reported in the literature.
The Paradigm of Sudden Death Prevention in Hypertrophic Cardiomyopathy
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Hypertrophic cardiomyopathy (HCM) is a relatively common and, often, inherited cardiac disease, once regarded as largely untreatable with ominous prognosis and, perhaps, most visibly as a common cause of sudden cardiac death (SCD) in the young. However, HCM is now more accurately considered a treatable disease with management options that significantly alter its clinical course. This is particularly true for SCD because the penetration of implantable cardioverter-defibrillators into HCM practice enables primary prevention device therapy that reliably terminates potentially lethal ventricular tachyarrhythmias (3% to 4%/year). This therapeutic advance is largely responsible for >10-fold decrease in the overall disease-related mortality to 0.5%/year, independent of patient age. A guideline-based clinical risk stratification algorithm has evolved, which included variables identifiable with cardiac magnetic resonance: ≥1 risk markers judged major within the clinical profile of an individual patient, associated with a measure of physician judgment and shared decision-making, can be sufficient to consider the recommendation of a prophylactic defibrillator implant. Implantable cardioverter-defibrillator decisions using the American College of Cardiology and the American Heart Association traditional major risk marker strategy are associated with a 95% sensitivity for identifying those patients who subsequently experience appropriate therapy, albeit often 5 to 10+ years after implant but without heart failure deterioration or death after a device intervention. A mathematical SCD risk score proposed by European Society of Cardiology is associated with a relatively low sensitivity (33%) for predicting and preventing SCD events but with potential for less device overtreatment.
Progression of Late Gadolinium Enhancement in Hypertrophic Cardiomyopathy: Another Piece of the Puzzle
2024, American Journal of Cardiology
Prognostic Role of the Progression of Late Gadolinium Enhancement in Hypertrophic Cardiomyopathy
2024, American Journal of Cardiology
In hypertrophic cardiomyopathy (HCM), late gadolinium enhancement (LGE) extent ≥15% of left ventricular mass is considered a prognostic risk factor. LGE extent increases over time and the clinical role of the progression of LGE over time (LGE rate) was not prospectively evaluated. We sought to evaluate the prognostic role of the LGE rate in HCM. We enrolled 105 patients with HCM who underwent cardiac magnetic resonance (CMR) at baseline (CMR-I) and after ≥2 years of follow-up (CMR-II). LGE rate was defined as the ratio between the increase of LGE extent (grams) and the time interval (months) between examinations. A combined end point of sudden cardiac death, resuscitated cardiac arrest, appropriate Implanted Cardioverter Defibrillator (ICD) intervention, and sustained ventricular tachycardia was used (hard events). The percentage of patients with LGE extent ≥15% increased from 9% to 20% from CMR-I to CMR-II (p = 0.03). During a median follow-up of 52 months, 25 hard events were recorded. The presence of LGE ≥15% at CMR-II allowed a significant reclassification of the risk of patients than at LGE ≥15% at CMR-I (net reclassification improvement 0.21, p = 0.046). On the MaxStat analysis, the optimal prognostic cut point for LGE rate was >0.07 g/month. On the Kaplan–Meier curve, patients with LGE rate >0.07 had worse prognosis than those without (p <0.0001). LGE rate >0.07 allowed a significant reclassification of the risk compared with LGE ≥15% at CMR-I and at CMR-II (net reclassification improvement 0.49, p = 0.003). In the multivariable models, LGE rate >0.07 was the best independent predictor of hard events. In conclusion, CMR should be repeated after 2 years to reclassify the risk for sudden death of those patients. A high LGE rate may be considered a novel prognostic factor in HCM.
The challenge of risk stratification in hypertrophic cardiomyopathy: Clinical, genetic and imaging insights from a quaternary referral centre
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Hypertrophic cardiomyopathy (HCM) is the commonest genetic cardiomyopathy and may result in sudden cardiac death (SCD). Clinical risk stratification scores are utilised to estimate SCD risk and determine potential utility of a primary prevention implantable cardioverter defibrillator (ICD).
Patients with a confirmed diagnosis of HCM from a quaternary HCM service were defined according to clinical characteristics, genetic profiles and cardiac imaging results. European Risk-SCD score and American Heart Association / American College of Cardiology (AHA/ACC) Score were calculated. The primary outcome was cardiac arrest.
380 patients with HCM were followed up for a median of 6.4 years. 18 patients (4.7%) experienced cardiac arrest, with predictive factors being younger age (37.2 vs 54.4 years, p = 0.0041), unexplained syncope (33.3% vs 9.4%, p = 0.007), non-sustained ventricular tachycardia (50.0% vs 12.7%, p < 0.0001), increased septal thickness (21.5 vs 17.5 mm, p = 0.0003), and presence of a sarcomeric gene mutation (100.0% vs 65.8%, p = 0.038). The Risk-SCD and AHA/ACC scores had poor agreement (kappa coefficient 0.38). Risk-SCD score had poor sensitivity (44.4%), classifying 55.6% of patients with cardiac arrest as low-risk but was highly specific (93.7%). AHA/ACC risk score did not discriminate between groups significantly. 20 patients (5.3%) died, with most >60-year-olds having a non-cardiac cause of death (p = 0.0223).
This study highlights limited (38%) agreement between the Risk-SCD and AHA/ACC scores. Most cardiac arrests occurred in ostensibly low or medium-risk patients under both scores. Appropriate ICD selection remains challenging. Incorporating newer risk markers such as HCM genotyping and myocardial fibrosis quantification by cardiac MRI may assist future risk refinement.
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CardiomyopathyIndependent Assessment of the European Society of Cardiology Sudden Death Risk Model for Hypertrophic Cardiomyopathy

Section snippets

Methods

Results

Discussion

Disclosures

J Am Coll Cardiol

Lancet

J Am Coll Cardiol

Am J Cardiol

J Am Coll Cardiol

J Am Coll Cardiol

Am Heart J

J Am Coll Cardiol

Heart Rhythm

J Am Coll Cardiol

J Am Coll Cardiol

J Am Coll Cardiol

J Am Coll Cardiol

JACC Cardiovasc Imaging

Am J Cardiol

Am J Cardiol

Am J Cardiol

Am J Cardiol

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Cardiomyopathy
Independent Assessment of the European Society of Cardiology Sudden Death Risk Model for Hypertrophic Cardiomyopathy