Christopher Jer Wei Low

Objectives: Cardiogenic shock is a time-critical emergency requiring aggressive therapeutic interventions, yet prognostication remains challenging with no consensus on the comparative applicabilities of risk scores. Our study aims to evaluate the capacities of existing risk scores for efficient, effective, and generalizable prognostication of mortality across various patient demographic cohorts. Data Sources: We searched MEDLINE, Embase, and Scopus databases up to June 15, 2024. Study Selection: We included articles developing, redeveloping, or validating a multivariable model predicting all-cause mortality in adults with cardiogenic shock. Data Extraction: We pooled area under the curve (AUC) statistics and observed: expected (O:E) ratios as an assessment of discrimination and calibration, respectively. We conducted random-effects inverse-variance weighted meta-analyses on prespecified prediction models (Intra-Aortic Balloon Counterpulsation in Acute Myocardial Infarction Complicated by Cardiogenic Shock [IABP-SHOCK II], CardShock, Simplified Acute Physiology Score II, Sequential Organ Failure Assessment, Acute Physiology and Chronic Health Evaluation II, and Survival After Venoarterial Extracorporeal Membrane Oxygenation) to derive pooled estimates of AUCs and aggregate O:Es for each model. Subgroup analyses were conducted to identify sources of heterogeneity. Data Synthesis: We included 102 studies comprising 126 study cohorts in our final analysis (89,546 patients), with 40 unique prediction models identified. There were no significant differences between the performances of all included scores. However, in terms of absolute pooled values, CardShock score had the highest pooled discrimination (AUC, 0.73 [95% CI, 0.70–0.76]) and best calibration (O:E, 1.06 [95% CI, 0.79–1.41]) among other widely used scores. Subgroup analyses were highly variable between studies and again did not reveal a superior prediction model. Unique prediction models developed by authors were found to be superior to existing prediction models, yet lacked generalizability. Conclusions: Meta-analysis of six included scores revealed no clear “gold standard” prediction model, although the CardShock score had the highest discrimination and most accurate calibration. The degree of variability between studies precluded in-depth assessment of subgroup analysis. Further research into novel risk scores can be conducted to better inform clinicians on their utility.

Purpose Cardiogenic shock is associated with high mortality. In refractory shock, it is unclear if mechanical circulatory support (MCS) devices improve survival. We conducted a network meta-analysis to determine which MCS devices confers greatest benefit. Methods We searched MEDLINE, Embase, and Scopus databases through 27 August 2023 for relevant randomized controlled trials (RCTs) and propensity score-matched studies (PSMs). We conducted frequentist network meta-analysis, investigating mortality (either 30 days or in-hospital) as the primary outcome. We assessed risk of bias (Cochrane risk of bias 2.0 tool/Newcastle–Ottawa Scale) and as sensitivity analysis reconstructed survival data from published survival curves for a one-stage unadjusted individual patient data (IPD) meta-analysis using a stratified Cox model. Results We included 38 studies (48,749 patients), mostly reporting on patients with Society for Cardiovascular Angiography and Intervention shock stages C–E cardiogenic shock. Compared with no MCS, extracorporeal membrane oxygenation with intra-aortic balloon pump (ECMO-IABP; network odds ratio [OR]: 0.54, 95% confidence interval (CI): 0.33–0.86, moderate certainty) was associated with lower mortality. There were no differences in mortality between ECMO, IABP, microaxial ventricular assist device (mVAD), ECMO-mVAD, centrifugal VAD, or mVAD-IABP and no MCS (all very low certainty). Our one-stage IPD survival meta-analysis based on the stratified Cox model found only ECMO-IABP was associated with lower mortality (hazard ratio, HR, 0.55, 95% CI 0.46–0.66). Conclusion In patients with cardiogenic shock, ECMO-IABP may reduce mortality, while other MCS devices did not reduce mortality. However, this must be interpreted within the context of inter-study heterogeneity and limited certainty of evidence.

Background: With ideal mean arterial pressure (MAP) targets in resuscitated out-of-hospital cardiac arrest (OHCA) patients unknown, we performed a meta-analysis of randomised controlled trials (RCTs) to compare the effects of higher versus lower MAP targets. Methods: We searched four databases until 1 May 2023 for RCTs reporting the effects of higher MAP targets (>70 mmHg) in resuscitated OHCA patients and conducted random-effects meta-analyses. The primary outcome was mortality while secondary outcomes were neurological evaluations, arrhythmias, acute kidney injury, and durations of mechanical ventilation and ICU stay. We conducted inverse-variance weighted strata-level meta-regression against a proportion of non-survivors to assess differences between reported MAPs. We also conducted a trial sequential analysis of RCTs. Results: Four RCTs were included. Higher MAP was not associated with reduced mortality (OR: 1.09, 95%-CI: 0.84 to 1.42, p = 0.51), or improved neurological outcomes (OR: 0.99, 95%-CI: 0.77 to 1.27, p = 0.92). Such findings were consistent despite additional sensitivity analyses. Our robust variance strata-level meta-regression revealed no significant associations between mean MAP and the proportion of non-survivors (B: 0.029, 95%-CI: −0.023 to 0.081, p = 0.162), and trial sequential analysis revealed no meaningful survival benefit for higher MAPs. Conclusions: A higher MAP target was not significantly associated with improved mortality and neurological outcomes in resuscitated OHCA patients.

Microaxial left ventricular assist devices (LVAD) are increasingly used to support patients with cardiogenic shock; however, outcome results are limited to single-center studies, registry data and select reviews. We conducted a systematic review and meta-analysis, searching three databases for relevant studies reporting on microaxial LVAD use in adults with cardiogenic shock. We conducted a random-effects meta-analysis (DerSimonian and Laird) based on short-term mortality (primary outcome), long-term mortality and device complications (secondary outcomes). We assessed the risk of bias and certainty of evidence using the Joanna Briggs Institute and the GRADE approaches, respectively. A total of 63 observational studies (3896 patients), 6 propensity-score matched (PSM) studies and 2 randomized controlled trials (RCTs) were included (384 patients). The pooled short-term mortality from observational studies was 46.5% (95%-CI: 42.7–50.3%); this was 48.9% (95%-CI: 43.8–54.1%) amongst PSM studies and RCTs. The pooled mortality at 90 days, 6 months and 1 year was 41.8%, 51.1% and 54.3%, respectively. Hemolysis and access-site bleeding were the most common complications, each with a pooled incidence of around 20%. The reported mortality rate of microaxial LVADs was not significantly lower than extracorporeal membrane oxygenation (ECMO) or intra-aortic balloon pumps (IABP). Current evidence does not suggest any mortality benefit when compared to ECMO or IABP.