Log in to MyACC
Acute Noncardiac Organ Failure in AMI With Cardiogenic Shock
Study Questions:
What are the national trends in prevalence, outcomes, and resource utilization for noncardiac organ failure after cardiogenic shock (CS) due to acute myocardial infarction (AMI) over the last 15 years?
Methods:
This was a retrospective observational study using the Nationwide Inpatient Sample, which is the largest all-payer database of hospital inpatient stays in the United States. Patients hospitalized with cardiogenic shock (CS) and AMI were identified using International Classification of Diseases (ICD)-9 codes from 2000-2014. Noncardiac organ failure was also identified using validated ICD-9 codes. The primary outcome of interest was in-hospital mortality stratified by no organ failure, single organ failure, or multiorgan failure (≥2 organ systems involved) in noncardiac systems. Secondary outcomes included prevalence of organ failure, length of stay, costs, and discharge disposition.
Results:
Between January 1, 2000 and December 31, 2014, there were approximately 9 million admissions with ICD-9 codes for AMI, of which 4.6% of admissions (n = 443,253) also had diagnostic codes for CS. Among patients with AMI-CS, acute noncardiac organ failure was present in 64.3% of admissions with 31.9% admissions having multiorgan failure. Noncardiac multiorgan failure was more common in patients with non-ST-segment elevation MI, nonwhite race, and higher baseline comorbidity. The prevalence of multi noncardiac organ failure increased from 15.7% in 2000 to 45.5% in 2014, with a concomitant decline in admissions with single or no organ failure. Most common systems involved were respiratory (43.4%) and renal (35.2%).
Admissions with other organ failure had higher rates of cardiac arrest, use of invasive hemodynamic monitoring, and mechanical circulatory support devices. However, presence of a single or multiorgan failure was associated with lower use of coronary angiography despite multivariable adjustment (odds ratio [OR], 0.79; 95% confidence interval [CI], 0.78-0.81 and OR, 0.68; 95% CI, 0.67-0.70, respectively).
Compared to patients with CS without any other organ involvement, in-hospital mortality was higher in single (adjusted OR, 1.28; 95% CI, 1.26-1.30) and multiorgan failure (adjusted OR, 2.23; 95% CI, 2.19-2.27). Increasing organ failure was associated with longer length of stay, higher costs, and a lower likelihood of home discharge. Involvement of each additional organ system failure was associated with a stepwise increase in adjusted odds of in-hospital mortality, increased length of stay, and hospitalization costs.
Conclusions:
In a large retrospective analysis of an administrative claims data set, patients with AMI-CS from 2000-2014 had an increasing prevalence of multiorgan failure with a lower prevalence of single or no noncardiac organ involvement. Prevalence of single or multiorgan failure was independently associated with a lower likelihood of receiving a coronary angiogram. Compared to AMI-CS patients without other organ involvement, patients with single-organ failure had 1.3 higher odds for in-hospital mortality and patients with multiple organ failure had 2.9 higher odds for in-hospital mortality. In addition, involvement of noncardiac organs correlated with increased length of stay and in-hospital cost.
Perspective:
Despite improvement in AMI care, in-hospital mortality rates in patients with AMI-CS remain high at 30-45%. One potential reason for these high mortality rates includes the initial hemodynamic insult evolves into a metabolic insult, leading to hypoperfusion with multiorgan failure. In this large, retrospective, administrative claims cohort study, the authors stratified AMI-CS into patients without other organ system involvement, single-organ, and multiorgan failure. Major limitations of this study include its retrospective nature and use of administrative claims data, which lowers sensitivity for detecting other organ system involvement.
Nonetheless, this study offers important insights into real-world AMI-CS patients. Over the study period of 2000-2014, the proportion of patients with multiorgan failure increased, while patients with no noncardiac organ failure and single-organ failure declined, reflecting that the contemporary AMI-CS population is sicker. Furthermore, presence of single or multiple noncardiac organ failure was independently associated with lower odds for undergoing a coronary angiogram. Due to the retrospective nature of this study, a cause-effect relationship cannot be assumed and it is possible that comorbidities precluded coronary angiogram for AMI-CS.
Involvement of other noncardiac organ systems was independently associated with higher odds for in-hospital mortality, higher cost, and lower likelihood of discharging home. It is noteworthy that contemporary AMI risk stratification scores rely primarily on angiographic and hemodynamic data with newer systems incorporating lab data such as creatinine. However, future studies should look into including involvement of other organ systems more comprehensively as prognostic markers.
Clinical Topics: Acute Coronary Syndromes, Arrhythmias and Clinical EP, Cardiovascular Care Team, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Implantable Devices, SCD/Ventricular Arrhythmias, Acute Heart Failure, Interventions and ACS, Interventions and Imaging, Angiography, Nuclear Imaging
Keywords: Acute Coronary Syndrome, Comorbidity, Coronary Angiography, Creatinine, Heart Arrest, Heart Failure, Hemodynamics, Hospital Mortality, Inpatients, Length of Stay, Multiple Organ Failure, Myocardial Infarction, Patient Discharge, Risk, Shock, Cardiogenic
< Back to Listings
