Further Research May Improve Long-Term Survival with Out-of-Hospital Cardiac Arrest

Additionally research may be necessary to improve the long-term survival of patients with out-of-hospital cardiac arrest (OHCA), according to new findings.

Data from a comprehensive systematic review and meta-analysis found the rate of long-term survival after 10 years in patients surviving the initial hospital stay after OHCA was between 62% and 64%.

“Based on observational data, patients with OHCA have significantly lower long-term survival when compared with age- and sex-matched cohorts or an unselected overall population, especially during the first year after OHCA,” wrote study author Sabina Hunziker, MD, MPH, Intensive Care, University Hospital Basel.

Alongside efforts to improve initial survival after OCHA, there is increased interest in better understanding and improving longer-term outcomes in this population. However, large-scale research of survival beyond 1-year is lacking.

The current study assessed pooled reconstructed patient data (RPD) of long-term survival after OHCA beyond 1 year and compiled data on potential factors associated with long-term survival after OHCA.

In terms of the primary analysis, the current study’s focus was on long-term survival after hospital discharge or 30 days after OHCA. A secondary analysis zeroed in on long-term survival after hospital admission.

The inclusion criteria consisted of adult patients (≥18 years of age) with OHCA, survival to hospital admission (including intensive care unit [ICU] admission), or until hospital discharge or until 30 days after OHCA, and reporting of survival beyond 12 months.

In the analysis, patient data were reconstructed from Kaplan-Meier curves using an iterative algorithm and pooled to generate survival curves. Then, as a separate analysis, an aggregate data meta-analysis was performed.

A total of 21 studies with 11,800 patients were used for the Kaplan-Meier-based meta-analysis and 33 studies with 16,933 patients were used for the aggregate data meta-analysis.

Within the Kaplan-Meier-based analysis, the median survival time for patients surviving to hospital discharge was 5.0 years (IQR, 2.3 - 7.9 years). Data show the estimated survival rates were 82.8% (95% confidence interval [CI], 81.9% - 83.7%) at 3 years, 77.0% (95% CI, 75.9% - 78.0%) at 5 years, 63.9% (95% CI, 62.3% - 65.4%) at 10 years, and 57.5% (95% CI, 54.8% - 60.1%) at 15 years.

Then, compared with patients with a nonshockable initial rhythm, patients with a shockable initial rhythm had a significantly better long-term survival (HR, 0.30; 95% CI, 0.23 - 0.39; P <.001).

Regarding long-term survival after hospital or ICU admission, a total of 2150 deaths occurred during a total observation time of 5753 person-years. The median survival was 0.1 years (IQR, 0.0 - 3.0 years) with a 5-year survival rate of 32.6% (95% CI, 30.8% - 34.4%) and a 10-year survival rate of 28.2% (95% CI, 25.7% - 30.7%).

Different analyses, including an aggregate data meta-analysis confirmed the results, according to study investigators.

The study, “Long-term Survival After Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-analysis,” was published in JAMA Cardiology.