Prevention of Sudden Cardiac Death in Hypertrophic Cardiomyopathy: What has Changed in The Guidelines?

Abstract

BackgroundThe new European Society of Cardiology guidelines for hypertrophic cardiomyopathy (HCM) define the estimation of sudden cardiac death (SCD) risk as an integral part of clinical management. An implantable cardioverter defibrillator (ICD) is recommended (class IIa) when the risk is ≥ 6%.ObjectivesTo compare the SCD risk stratification according to the 2011 and 2014 recommendations for ICD implantation in patients with HCM.MethodsRetrospective study including 105 patients diagnosed with HCM. The indication for ICD was assessed using the 2011 and 2014 guidelines. Statistical analysis was performed using SPSS software version 19.0.0.2®. The tests performed were bilateral, considering the significance level of 5% (p < 0.05).ResultsRegarding primary prevention, according to the 2011 ACCF/AHA recommendations, 39.0% of the patients had indication for ICD implantation (level of evidence IIa). Using the 2014 guidelines, only 12.4% of the patients had an indication for ICD implantation. Comparing the two risk stratification models for patients with HCM, we detected a significant reduction in the number of indications for ICD implantation (p < 0.001). Of the 41 patients classified as IIa according to the 2011 recommendations, 68.3% received a different classification according to the 2014 guidelines.ConclusionSignificant differences were found when comparing the SCD risk stratification for ICD implantation in the two guidelines. The current SCD risk score seems to identify many low-risk patients who are not candidates for ICD implantation. The use of this new score results in a significant reduction in the number of ICD implanted.

Discordância entre Diretrizes Internacionais sobre Critérios de Prevenção Primária de Morte Súbita na Cardiomiopatia Hipertrófica

“…[24][25][26][27][28] Other studies point out the sensitivity of low score for the recognition of high-risk patients, the capacity to identify cases with an ICD unwarranted and the similar event rates observed in the three risk levels. [29][30][31][32] Our study supports these findings demonstrating that the European model decreases the ICD recommendations compared to the North American guideline, leaves all patients with SCD or appropriate shock unprotected and establishes major agreement in cases not requiring implantation. Nevertheless, the metanalysis of six studies conducted with 7,291 patients demonstrates that in most cases, the five-year SCD risk is properly estimated with the ESC score.…”