Determinants of Undertaking Coronary Angiography and Adverse Prognostic Predictors Among Patients Presenting With Out-of-Hospital Cardiac Arrest and a Shockable Rhythm

Development of an Acute Coronary Syndrome-Cardiogenic Shock Risk Score for 30-day Mortality From the Victorian Cardiac Outcomes Registry (VCOR ACS-CS Risk Score)

INTRODUCTION

Acute coronary syndrome-cardiogenic shock (ACS-CS) confers a 30-day mortality rate of ~50%. A simple bed-side risk score for 30-day all-cause mortality may aid in rapid prognostication in these high-risk patients.

METHODS

We analyzed data from consecutive patients with ACS-CS enrolled in the Victorian Cardiac Outcomes Registry (VCOR), a state-wide procedure-based clinical quality registry, between 2013 and 2021. Internal validation was performed in 1000 bootstrapped samples to derive variables that were in > 60% of models for the prediction of 30-day mortality. Model performance was evaluated using C-statistic, and Hosmer Lemeshow (HL) statistic.

RESULTS

Of 1564 patients with ACS-CS undergoing percutaneous coronary intervention (PCI), 1403 presented with ST-elevation myocardial infarction (STEMI) and 161 with non-STEMI. Age was 66 ± 13 years, and 74% were males. In-hospital and 30-day mortality rates were 42% and 45%. Selected predictors of 30-day mortality included age (odds ratio (OR) 1.4 [1.3, 1.6] per 10 year increase), female sex (OR 1.4 [1.1, 1.8]), diabetes (OR 1.5 [1.2, 2.0]), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (OR 2.2 [1.3, 3.5]), <60 mL/min/1.73 m2 (OR 1.5 [1.1, 2.0], left ventricular ejection fraction < 35% (OR 4.6 [3.5, 6.1]), out-of-hospital cardiac arrest (OR 2.3 [1.8, 3.1]), pre-procedural intubation (OR 2.1 [1.6, 2.7], mechanical circulatory support (OR 1.5 [1.1, 2.1]), STEMI (OR 2.6 [1.7, 3.8]), and multivessel PCI (OR 1.5 [1.1, 2.1], all p < 0.01). Internal validation of 1000 bootstrapped samples resulted in 15 clinical and procedural variables, which demonstrated excellent fit and performance (C-statistic = 0.8, HL p = 0.44) for the prediction of 30-day mortality.

CONCLUSION

A risk score incorporating only peri-procedural (clinical and procedural) variables accurately stratified 30-day mortality risk among patients with ACS-CS who underwent PCI. Further studies are required to externally validate the VCOR ACS-CS risk score, however, its simplicity potentially facilitates translation into clinical practice.

Clinical Features and Outcomes Among Patients With Refractory Out-of-Hospital Cardiac Arrest and an Initial Shockable Rhythm

BACKGROUND

Clinical features among patients with refractory out-of-hospital cardiac arrest (OHCA) and initial shockable rhythms of ventricular fibrillation/pulseless ventricular tachycardia are not well-characterized.

METHODS

We compared clinical characteristics and coronary angiographic findings between patients with refractory OHCA (incessant ventricular fibrillation/pulseless ventricular tachycardia after ≥3 direct-current shocks) and those without refractory OHCA.

RESULTS

Between 2014 and 2018, a total of 204 patients with ventricular fibrillation/pulseless ventricular tachycardia OHCA (median age 62; males 78%) were divided into groups with (36%, 74/204) and without refractory arrest (64%, 130/204). Refractory OHCA patients had longer cardiopulmonary resuscitation (23 versus 15 minutes), more frequently required ≥450 mg amiodarone (34% versus 3.8%), and had cardiogenic shock (80% versus 55%) necessitating higher adrenaline dose (4.0 versus 1.0 mg) and higher rates of mechanical ventilation (92% versus 74%; all P<0.01). Of 167 patients (82%) selected for coronary angiography, 33% (n=55) had refractory OHCA (P=0.035). Significant coronary artery disease (≥1 major vessel with >70% stenosis) was present in >70% of patients. Refractory OHCA patients frequently had acute coronary occlusion (64% versus 47%), especially left circumflex (20% versus 6.4%) and graft vessel (7.3% versus 0.9%; all P<0.05) compared with those without refractory OHCA. Refractory OHCA group had higher in-hospital mortality (45% versus 30%, P=0.036) and greater new requirement for dialysis (18% versus 6.3%, P=0.011). After adjustment, refractory OHCA was associated with over 2-fold higher odds of in-hospital mortality (odds ratio, 2.28 [95% CI, 1.06-4.89]; P=0.034).

CONCLUSIONS

Refractory ventricular fibrillation/pulseless ventricular tachycardia OHCA was associated with more intensive resuscitation, higher rates of acute coronary occlusion, and poorer in-hospital outcomes, underscoring the need for future studies in this extreme-risk subgroup.

Effect of Concomitant Cardiac Arrest on Outcomes in Patients With Acute Coronary Syndrome-Related Cardiogenic Shock

Patients with acute coronary syndrome (ACS)-related cardiogenic shock (CS) with or without concomitant CA may have disparate prognoses. We compared clinical characteristics and outcomes of patients with CS secondary to ACS with and without cardiac arrest (CA). Between 2014 and 2020, 1,573 patients with ACS-related CS with or without CA who underwent percutaneous coronary intervention enrolled in a multicenter Australian registry were analyzed. Primary outcome was 30-day major adverse cardiovascular and cerebrovascular events (MACCE) (composite of mortality, myocardial infarction, stent thrombosis, target vessel revascularization and stroke). Long-term mortality was obtained through linkage to the National Death Index. Compared with the no-CA group (n = 769, 49%), the CA group (n = 804, 51%) was younger (62 vs 69 years, p <0.001) and had fewer comorbidities. Patients with CA more frequently had ST-elevation myocardial infarction (92% vs 86%), occluded left anterior descending artery (43% vs 33%), and severe preprocedural renal impairment (49% vs 42%) (all p <0.001). CA increased risk of 30-day MACCE by 45% (odds ratio 1.45, 95% confidence interval 1.05 to 2.00, p = 0.024) after adjustment. CA group had higher 30-day MACCE (55% vs 42%, p <0.001) and mortality (52% vs 37%, p <0.001). Three-year survival was lower for CA compared with no-CA patients (43% vs 52%, p <0.001). In Cox regression, CS with CA was associated with a trend toward greater long-term mortality hazard (hazard ratio 1.19, 95% confidence interval 1.00 to 1.41, p = 0.055). In conclusion, concomitant CA among patients with ACS-related CS conferred a particularly heightened short-term risk with a diminishing legacy effect over time for mortality. CS survivors continue to exhibit high sustained long-term mortality hazard regardless of CA status.

Sex differences among patients presenting to hospital with out-of-hospital cardiac arrest and shockable rhythm

OBJECTIVE

Sex differences in patients presenting with out-of-hospital cardiac arrest (OHCA) and shockable rhythm might be associated with disparities in clinical outcomes.

METHODS

We conducted a retrospective cohort study and compared characteristics and short-term outcomes between male and female adult patients who presented with OHCA and shockable rhythm at two large metropolitan health services in Melbourne, Australia between the period of 2014-2018. Logistic regression was used to assess the effect of sex on clinical outcomes.

RESULTS

Of 212 patients, 166 (78%) were males and 46 (22%) were females. Both males and females presented with similar rates of ST-elevation myocardial infarction (44% vs 36%, P = 0.29), although males were more likely to have a history of coronary artery disease (32% vs 13%) and a final diagnosis of a cardiac cause for their OHCA (89% vs 72%), both P = 0.01. Rates of coronary angiography (81% vs 71%, P = 0.23) and percutaneous coronary intervention (51% vs 42%, P = 0.37) were comparable among males and females. No differences in rates of in-hospital mortality (38% vs 37%, P = 0.90) and 30-day major adverse cardiac and cerebrovascular events (composite of all-cause mortality, myocardial infarction, coronary revascularization and nonfatal stroke) (39% vs 41%, P = 0.79) were observed between males and females, respectively. Female sex was not associated with worse in-hospital mortality when adjusted for other variables (odds ratio 0.66, 95% confidence interval 0.28-1.60, P = 0.36).

CONCLUSION

Among patients presenting with OHCA and a shockable rhythm, baseline sex and sex differences were not associated with disparities in short-term outcomes in contemporary systems of care.

Evaluation of factors associated with selection for coronary angiography and in-hospital mortality among patients presenting with out-of-hospital cardiac arrest without ST-segment elevation

BACKGROUND

Clinical factors favouring coronary angiography (CA) selection and variables associated with in-hospital mortality among patients presenting with out-of-hospital cardiac arrest (OHCA) without ST-segment elevation (STE) remain unclear.

METHODS

We evaluated clinical characteristics associated with CA selection and in-hospital mortality in patients with OHCA, shockable rhythm and no STE.

RESULTS

Between 2014 and 2018, 118 patients with OHCA and shockable rhythm without STE (mean age 59; males 75%) were stratified by whether CA was performed. Of 86 (73%) patients undergoing CA, 30 (35%) received percutaneous coronary intervention (PCI). CA patients had shorter return of spontaneous circulation (ROSC) time (17 vs. 25 min) and were more frequently between 50 and 60 years (29% vs. 6.5%), with initial Glasgow Coma Scale (GCS) score >8 (24% vs. 6%) (all p < 0.05). In-hospital mortality was 33% (n = 39) for overall cohort (CA 27% vs. no-CA 50%, p = 0.02). Compared to late CA, early CA ( ≤ 2 h) was not associated with lower in-hospital mortality (32% vs. 34%, p = 0.82). Predictors of in-hospital mortality included longer defibrillation time (odds ratio 3.07, 95% confidence interval 1.44-6.53 per 5-min increase), lower pH (2.02, 1.33-3.09 per 0.1 decrease), hypoalbuminemia (2.02, 1.03-3.95 per 5 g/L decrease), and baseline renal dysfunction (1.33, 1.02-1.72 per 10 ml/min/1.73 m² decrease), while PCI to lesion (0.11, 0.01-0.79) and bystander defibrillation (0.06, 0.004-0.80) were protective factors (all p < 0.05).

CONCLUSIONS

Among patients with OHCA and shockable rhythm without STE, younger age, shorter time to ROSC and GCS >8 were associated with CA selection, while less effective resuscitation, greater burden of comorbidities and absence of treatable coronary lesion were key adverse prognostic predictors.

Impella versus Venoarterial Extracorporeal Membrane Oxygenation for Acute Myocardial Infarction Cardiogenic Shock: A Systematic Review and Meta-Analysis

Objectives: Despite an increase in the use of mechanical circulatory support (MCS) devices for acute myocardial infarction cardiogenic shock (AMI-CS), there is currently no randomised data directly comparing the use of Impella and veno-arterial extra-corporeal membrane oxygenation (VA-ECMO). Methods: Electronic databases of MEDLINE, EMBASE and CENTRAL were systematically searched in November 2021. Studies directly comparing the use of Impella (CP, 2.5 or 5.0) with VA-ECMO for AMI-CS were included. Studies examining other modalities of MCS, or other causes of cardiogenic shock, were excluded. The primary outcome was in-hospital mortality. Results: No randomised trials comparing VA-ECMO to Impella in patients with AMI-CS were identified. Six cohort studies (five retrospective and one prospective) were included for systematic review. All studies, including 7093 patients, were included in meta-analysis. Five studies reported in-hospital mortality, which, when pooled, was 42.4% in the Impella group versus 50.1% in the VA-ECMO group. Impella support for AMI-CS was associated with an 11% relative risk reduction in in-hospital mortality compared to VA-ECMO (risk ratio 0.89; 95% CI 0.83–0.96, I² 0%). Of the six studies, three studies also adjusted outcome measures via propensity-score matching with reported reductions in in-hospital mortality with Impella compared to VA-ECMO (risk ratio 0.72; 95% CI 0.59–0.86, I² 35%). Pooled analysis of five studies with 6- or 12-month mortality data reported a 14% risk reduction with Impella over the medium-to-long-term (risk ratio 0.86; 95% CI 0.76–0.97, I² 0%). Conclusions: There is no high-level evidence comparing VA-ECMO and Impella in AMI-CS. In available observation studies, MCS with Impella was associated with a reduced risk of in-hospital and medium-term mortality as compared to VA-ECMO.