Regional Variation in the Management and Outcomes of Acute Myocardial Infarction With Cardiogenic Shock in the United States

Influence of seasons on the management and outcomes acute myocardial infarction: An 18-year US study

Background

There are limited data on the seasonal variation in acute myocardial infarction (AMI) in the contemporary literature.

Hypothesis

There would be decrease in the seasonal variation in the management and outcomes of AMI.

Methods

Adult (>18 years) AMI admissions were identified using the National Inpatient Sample (2000‐2017). Seasons were classified as spring, summer, fall, and winter. Outcomes of interest included prevalence, in‐hospital mortality, use of coronary angiography, and percutaneous coronary intervention (PCI). Subgroup analyses for type of AMI and patient characteristics were performed.

Results

Of the 10 880 856 AMI admissions, 24.3%, 22.9%, 22.2%, and 24.2% were admitted in spring, summer, fall, and winter, respectively. The four cohorts had comparable age, sex, race, and comorbidities distribution. Rates of coronary angiography and PCI were slightly but significantly lower in winter (62.6% and 40.7%) in comparison to the other seasons (64‐65% and 42‐43%, respectively) (P < .001). Compared to spring, winter admissions had higher in‐hospital mortality (adjusted odds ratio [aOR]: 1.07; 95% confidence interval [CI]: 1.06‐1.08), whereas summer (aOR 0.97; 95% CI 0.96‐0.98) and fall (aOR 0.98; 95% CI 0.97‐0.99) had slightly lower in‐hospital mortality (P < .001). ST‐segment elevation (10.0% vs 9.1%; aOR 1.07; 95% CI 1.06‐1.08) and non‐ST‐segment elevation (4.7% vs 4.2%; aOR 1.07; 95% CI 1.06‐1.09) AMI admissions in winter had higher in‐hospital mortality compared to spring (P < .001). The primary results were consistent when stratified by age, sex, race, geographic region, and admission year.

Conclusions

Compared to other seasons, winter admission was associated with higher in‐hospital mortality in AMI in the United States.

Reporting of sex as a variable in cardiovascular studies using cultured cells: A systematic review

Reporting the sex of biological material is critical for transparency and reproducibility in science. This study examined the reporting of the sex of cells used in cardiovascular studies. Articles from 16 cardiovascular journals that publish peer-reviewed studies in cardiovascular physiology and pharmacology in the year 2018 were systematically reviewed using terms "cultured" and "cells." Data were collected on the sex of cells, the species from which the cells were isolated, and the type of cells, and summarized as a systematic review. Sex was reported in 88 (38.6%) of the 228 studies meeting inclusion criteria. Reporting rates varied with Circulation, Cardiovascular Research and American Journal of Physiology: Heart and Circulatory Physiology having the highest rates of sex reporting (>50%). A majority of the studies used cells from male (54.5%) or both male and female animals (32.9%). Humans (31.8%), rats (20.4%), and mice (43.8%) were the most common sources for cells. Cardiac myocytes were the most commonly used cell type (37.0%). Overall reporting of sex of experimental material remains below 50% and is inconsistent among journals. Sex chromosomes in cells have the potential to affect protein expression and molecular signaling pathways and should be consistently reported.

Burden of Arrhythmias in Acute Myocardial Infarction Complicated by Cardiogenic Shock

There are limited data on arrhythmias in acute myocardial infarction with cardiogenic shock (AMI-CS). Using a 17-year AMI-CS population from the National Inpatient Sample, we identified common arrhythmias - atrial fibrillation (AF), atrial flutter, supraventricular tachycardia, ventricular tachycardia, ventricular fibrillation, and atrioventricular blocks (AVB). Admissions with concomitant cardiac surgery were excluded. Outcomes of interest included temporal trends, predictors, in-hospital mortality, and resource utilization in cohorts with and without arrhythmias. Of the 420,319 admissions with AMI-CS during 2000 to 2016, arrhythmias were noted in 213,718 (51%). AF (45%), ventricular tachycardia (35%) and ventricular fibrillation (30%) were the most common arrhythmias. Compared with those without, the cohort w`ith arrhythmias was more often male, of white race, with ST-segment elevation AMI-CS presentation, and had higher rates of cardiac arrest and acute organ failure (all p <0.001). Temporal trends of prevalence revealed a stable trend of atrial and ventricular arrhythmias and declining trend in AVB. The cohort with arrhythmias had higher unadjusted (42% vs 41%; odds ratio [OR] 1.03 [95% confidence interval 1.02 to 1.05]; p <0.001), but not adjusted (OR 1.01 [95% CI 0.99 to 1.03]; p = 0.22) in-hospital mortality compared with those without. The cohort with arrhythmias had longer hospital stay (9 ± 10 vs 7 ± 9 days; p <0.001) and higher hospitalization costs ($124,000 ± 146,000 vs $91,000 ± 115,000; p <0.001). In the cohort with arrhythmias, older age, female sex, non-white race, higher co-morbidity, presence of acute organ failure, and cardiac arrest, predicted higher in-hospital mortality. In conclusion, cardiac arrhythmias in AMI-CS are a marker of higher illness severity and are associated with greater resource utilization.

Weekend Effect in the Management and Outcomes of Acute Myocardial Infarction in the United States, 2000-2016

Objective

To assess the effects of weekend admission vs weekday admission on the management and outcomes of acute myocardial infarction (AMI).

Methods

Adult ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) hospital admissions were identified using the National (Nationwide) Inpatient Sample (2000-2016). Interhospital transfers were excluded. Timing of coronary angiography (CA) and percutaneous coronary intervention (PCI) relative to the day of admission was identified. Outcomes of interest included in-hospital mortality, receipt of early CA, timing of CA and PCI, resource utilization, and discharge disposition for weekend vs weekday admissions.

Results

Of the 9,041,819 AMI admissions, 2,406,876 (26.6%) occurred on weekends. Compared with 2000, in 2016 there was an increase in weekend STEMI (adjusted odds ratio [aOR], 1.12; 95% CI, 1.08-1.16; P<.001) but not NSTEMI (aOR, 1.01; 95% CI, 0.98-1.02; P=.21) admissions. Compared with weekday admissions, weekend admissions received comparable CA (59.9% vs 58.8%) and PCI (38.4% vs 37.6%) and specifically lower rates of early CA (hospital day 0) (26.0% vs 20.8%; P<.001). There was a steady increase in CA and PCI use during the 17-year period. Mean ± SD time to CA was higher in the weekend group vs the weekday group (1.2±1.8 vs 1.0±1.8 days; P<.001). Weekend admission did not influence in-hospital mortality (aOR, 1.01; 95% CI, 1.00-1.01; P=.05) but had fewer discharges to home (58.7% vs 59.7%; P<.001).

Conclusion

Despite small differences in CA and PCI, there were no differences in in-hospital mortality of AMI admissions on weekdays vs weekends in the United States in the contemporary era.

Sex Disparities in the Use and Outcomes of Temporary Mechanical Circulatory Support for Acute Myocardial Infarction-Cardiogenic Shock

Background

There are limited sex-specific data on patients receiving temporary mechanical circulatory support (MCS) for acute myocardial infarction-cardiogenic shock (AMI-CS).

Methods

All admissions with AMI-CS with MCS use were identified using the National Inpatient Sample from 2005 to 2016. Outcomes of interest included in-hospital mortality, discharge disposition, use of palliative care and do-not-resuscitate (DNR) status, and receipt of durable left ventricular assist device (LVAD) and cardiac transplantation.

Results

In AMI-CS admissions during this 12-year period, MCS was used more frequently in men-50.4% vs 39.5%; P < 0.001. Of the 173,473 who received MCS (32% women), intra-aortic balloon pumps, percutaneous LVAD, extracorporeal membrane oxygenation, and ≥ 2 MCS devices were used in 92%, 4%, 1%, and 3%, respectively. Women were on average older (69 ± 12 vs 64 ± 13 years), of black race (10% vs 6%), and had more comorbidity (mean Charlson comorbidity index 5.0 ± 2.0 vs 4.5 ± 2.1). Women had higher in-hospital mortality than men (34% vs 29%, adjusted odds ratio [OR]: 1.19, 95% confidence interval [CI]: 1.16-1.23; P < 0.001) overall, in intra-aortic balloon pumps users (OR: 1.20 [95% CI: 1.16-1.23]; P < 0.001), and percutaneous LVAD users (OR: 1.75 [95% CI: 1.49-2.06]; P < 0.001), but not in extracorporeal membrane oxygenation or ≥ 2 MCS device users (P > 0.05). Women had higher use of palliative care, DNR status, and discharges to skilled nursing facilities.

Conclusions

There are persistent sex disparities in the outcomes of AMI-CS admissions receiving MCS support. Women have higher in-hospital mortality, palliative care consultation, and use of DNR status.

Complications in Patients with Acute Myocardial Infarction Supported with Extracorporeal Membrane Oxygenation

Background: There are limited data on complications in acute myocardial infarction (AMI) admissions receiving extracorporeal membrane oxygenation (ECMO). Methods: Adult (>18 years) admissions with AMI receiving ECMO support were identified from the National Inpatient Sample database between 2000 and 2016. Complications were classified as vascular, lower limb amputation, hematologic, and neurologic. Outcomes of interest included temporal trends, in-hospital mortality, hospitalization costs, and length of stay. Results: In this 17-year period, in ~10 million AMI admissions, ECMO support was used in 4608 admissions (<0.01%)—mean age 59.5 ± 11.0 years, 75.7% men, 58.9% white race. Median time to ECMO placement was 1 (interquartile range [IQR] 0–3) day. Complications were noted in 2571 (55.8%) admissions—vascular 6.1%, lower limb amputations 1.1%, hematologic 49.3%, and neurologic 9.9%. There was a steady increase in overall complications during the study period (21.1% in 2000 vs. 70.5% in 2016). The cohort with complications, compared to those without complications, had comparable adjusted in-hospital mortality (60.7% vs. 54.0%; adjusted odds ratio 0.89 [95% confidence interval 0.77–1.02]; p = 0.10) but longer median hospital stay (12 [IQR 5–24] vs. 7 [IQR 3–21] days), higher median hospitalization costs ($458,954 [IQR 260,522–737,871] vs. 302,255 [IQR 173,033–623,660]), fewer discharges to home (14.7% vs. 17.9%), and higher discharges to skilled nursing facilities (44.1% vs. 33.9%) (all p < 0.001). Conclusions: Over half of all AMI admissions receiving ECMO support develop one or more severe complications. Complications were associated with higher resource utilization during and after the index hospitalization.