Appropriate therapies predict long-term mortality in primary and secondary prevention of sudden cardiac death

Predictors of mortality and ICD shock therapy in primary prophylactic ICD patients-A systematic review and meta-analysis

Background

There is evidence that the benefit of a primary prophylactic ICD therapy is not equal in all patients.

Purpose

To evaluate risk factors of appropriate shocks and all- cause mortality in patients with a primary prophylactic ICD regarding contemporary studies.

Data source

PubMed, LIVIVO, Cochrane CENTRAL between 2010 and 2016.

Study selection

Studies were eligible if at least one of the endpoints of interest were reported.

Data extraction

All abstracts were independently reviewed by at least two authors. The full text of all selected studies was then analysed in detail.

Data synthesis

Our search strategy retrieved 608 abstracts. After exclusion of unsuitable studies, 36 papers with a total patient number of 47282 were included in our analysis. All-cause mortality was significantly associated with increasing age (HR 1.41, CI 1.29–1.53), left ventricular function (LVEF; HR 1.21, CI 1.14–1.29), ischemic cardiomyopathy (ICM; HR 1.37, CI 1.14–1.66) and co-morbidities such as impaired renal function (HR 2.30, CI 1.97–2.69). Although, younger age (HR 0.96, CI 0.85–1.09), impaired LVEF (HR 1.26, CI 0.89–1.78) and ischemic cardiomyopathy (HR 2.22, CI 0.83–5.93) were associated with a higher risk of appropriate shocks, none of these factors reached statistical significance.

Limitations

Individual patient data were not available for most studies.

Conclusion

In this meta-analysis of contemporary clinical studies, all-cause mortality is predicted by a variety of clinical characteristics including LVEF. On the other hand, the risk of appropriate shocks might be associated with impaired LVEF and ischemic cardiomyopathy. Further prospective studies are required to verify risk factors for appropriate shocks other than LVEF to help select appropriate patients for primary prophylactic ICD-therapy.

Gender Differences in Appropriate Shocks and Mortality among Patients with Primary Prophylactic Implantable Cardioverter-Defibrillators: Systematic Review and Meta-Analysis

Background

Some but not all prior studies have shown that women receiving a primary prophylactic implantable cardioverter defibrillator (ICD) have a lower risk of death and appropriate shocks than men.

Purpose

To evaluate the effect of gender on the risk of appropriate shock, all-cause mortality and inappropriate shock in contemporary studies of patients receiving a primary prophylactic ICD.

Data Source

PubMed, LIVIVO, Cochrane CENTRAL between 2010 and 2016.

Study Selection

Studies providing at least 1 gender-specific risk estimate for the outcomes of interest.

Data Extraction

Abstracts were screened independently for potentially eligible studies for inclusion. Thereby each abstract was reviewed by at least two authors.

Data Synthesis

Out of 680 abstracts retained by our search strategy, 20 studies including 46’657 patients had gender-specific information on at least one of the relevant endpoints. Mean age across the individual studies varied between 58 and 69 years. The proportion of women enrolled ranged from 10% to 30%. Across 6 available studies, women had a significantly lower risk of first appropriate shock compared with men (pooled multivariable adjusted hazard ratio 0.62 (95% CI [0.44; 0.88]). Across 14 studies reporting multivariable adjusted gender-specific hazard ratio estimates for all-cause mortality, women had a lower risk of death than men (pooled hazard ratio 0.75 (95% CI [0.66; 0.86]). There was no statistically significant difference for the incidence of first inappropriate shocks (3 studies, pooled hazard ratio 0.99 (95% CI [0.56; 1.73]).

Limitations

Individual patient data were not available for most studies.

Conclusion

In this large contemporary meta-analysis, women had a significantly lower risk of appropriate shocks and death than men, but a similar risk of inappropriate shocks. These data may help to select patients who benefit from primary prophylactic ICD implantation.

[Sudden cardiac death in individuals with normal hearts: an update]

Sudden death (SD) is a tragic event and a world-wide health problem. Every year, near 4-5 million people experience SD. SD is defined as the death occurred in 1h after the onset of symptoms in a person without previous signs of fatality. It can be named "recovered SD" when the case received medical attention, cardiac reanimation effective defibrillation or both, surviving the fatal arrhythmia. Cardiac channelopathies are a group of diseases characterized by abnormal ion channel function due to genetic mutations in ion channel genes, providing increased susceptibility to develop cardiac arrhythmias and SD. Usually the death occurs before 40 years of age and in the autopsy the heart is normal. In this review we discuss the main cardiac channelopathies involved in sudden cardiac death along with current management of cases and family members that have experienced such tragic event.