Faculty Bibliography

BACKGROUND:Perioperative cardiovascular events are a leading cause of morbidity and mortality after non-cardiac surgery. We propose a simplified method for perioperative risk stratification. METHODS:A retrospective cohort study identified patients undergoing non-cardiac surgery between 2009-2015 in the United States National Surgical Quality Improvement Program. Multivariable logistic regression models adjusted for age, sex, race and surgery type were generated to estimate the impact of traditional cardiovascular risk factors (hypertension, diabetes mellitus, current smoking) on odds of perioperative myocardial infarction (MI). Time to event analysis was conducted using competing risk analysis, with MI as the outcome event and death as the competing risk. RESULTS:A total of 3,848,501 non-cardiac surgeries were identified. Post-operative MI occurred in 0.37% of patients and 1.04% of patients died. The 30-day event rate of perioperative MI increased in a stepwise fashion with additional risk factors (0.41% for one, 0.81% for two, and 1.07% for three; P-for-trend < 0.001) after accounting for the competing risk of death. In comparison to those with no risk factors, patients with one, two and three risk factors had increased odds of MI (aOR 2.07; 95% CI 1.96-2.19; aOR 3.63 95% CI 3.43-3.85; aOR 5.54 95% CI 5.09-6.04). Perioperative MI was rare (0.10%) in patients without risk factors. CONCLUSIONS:Patients with cardiovascular risk factors are at increased risk of perioperative MI, those without risk factors are at low risk. Further evaluation is needed to determine the impact of a simplified risk score in the perioperative setting.

BACKGROUND:Heart failure (HF) affects ∼5.7 million United States adults and many of these patients develop non-cardiac disease that requires surgery. The aim of this study was to determine perioperative outcomes associated with HF in a large cohort of patients undergoing in-hospital non-cardiac surgery. METHODS:Adults ≥18 years old undergoing non-cardiac surgery between 2012-2014 were identified using the HCUP National Inpatient Sample. Patients with HF were identified by ICD-9 diagnosis codes. The primary outcome was all-cause in-hospital mortality. Multivariable logistic regression models were used to estimate associations between HF and outcomes. RESULTS:A total of 21,560,996 surgical hospitalizations were identified, of which 1,063,405 (4.9%) had a diagnosis of HF. Among hospitalizations with HF, 4.7% had acute HF, 11.3% had acute on chronic HF, 27.8% had chronic HF, and 56.2% had an indeterminate diagnosis code that did not specify temporality. In-hospital perioperative mortality was more common with a diagnosis of any HF compared to without HF (4.8% vs. 0.78%, p < 0.001; adjusted OR [aOR] 2.15 [95% CI 2.09-2.22]), and the association between HF and mortality was greatest at small and non-teaching hospitals. Acute HF without chronic HF was associated with 8.0% mortality. Among patients with a chronic HF diagnosis, perioperative mortality was greater in those with acute on chronic HF compared to chronic HF alone (7.8% vs. 3.9%, p < 0.001; aOR 1.78, 95% CI 1.67-1.90). CONCLUSION/CONCLUSIONS:In patients hospitalized for non-cardiac surgery, HF was common and was associated with increased risk of perioperative mortality. The greatest risks were in patients with acute HF.

Contemporary approaches to cardiovascular risk stratification before noncardiac surgery focus on macrovascular atherosclerotic disease and risk factors. We sought to determine the prevalence of microvascular disease (MVD) and its associated perioperative outcomes. Adults ≥18 years old undergoing noncardiac surgery between 2004 and 2014 were identified using the Nationwide Inpatient Sample (NIS). Prevalent MVD (retinopathy, neuropathy, and nephropathy) was identified by ICD-9 diagnosis codes. The primary outcomes were all-cause in-hospital mortality and the composite of major adverse cardiac events (MACE; death, myocardial infarction, and ischemic stroke). Multivariable logistic regression models were used to estimate associations between MVD and outcomes after adjusting for demographics and clinical covariates. Among 81,297,003 hospitalizations for noncardiac surgery, 4,236,932 (5.0%) had a diagnosis of MVD. Patients with MVD were older and more likely to have traditional cardiovascular risk factors. In-hospital perioperative MACE (4.1% vs. 1.9%; adjusted odds ratio [aOR] 1.15, 95% confidence interval [CI] 1.13 to 1.17) and mortality (2.0% vs. 1.1%; aOR 1.15, 95% CI 1.12 to 1.17) were greater in hospitalizations with MVD compared with those without. Microvascular disease was associated with postoperative outcomes in when stratified by age, sex, and coronary artery disease (CAD). Compared with surgical hospitalizations without CAD or MVD, MVD alone (aOR 1.12; 95% CI 1.11 to 1.14), CAD alone (aOR 1.44; 95% CI 1.42 to 1.46), and MVD with CAD (aOR 2.01; 95% CI 1.96 to 2.06) were associated with perioperative MACE. In conclusion, microvascular disease was present in 1 in 20 hospitalizations for noncardiac surgery, and was associated with perioperative mortality and MACE independent of macrovascular disease and traditional risk factors.

BACKGROUND:The Fourth Universal Definition of Myocardial Infarction (MI) differentiates MI from myocardial injury. We characterised the temporal course of cardiac and non-cardiac outcomes associated with MI, acute and chronic myocardial injury. METHODS:We included all patients presenting to public emergency departments in South Australia between June 2011-Sept 2019. Episodes of care (EOCs) were classified into 5 groups based on high-sensitivity troponin-T (hs-cTnT) and diagnostic codes: 1) Acute MI [rise/fall in hs-cTnT and primary diagnosis of acute coronary syndrome], 2) Acute myocardial injury with coronary artery disease (CAD) [rise/fall in hs-cTnT and diagnosis of CAD], 3) Acute myocardial injury without CAD [rise/fall in hs-cTnT without diagnosis of CAD], 4) Chronic myocardial injury [elevated hs-cTnT without rise/fall], and 5) No myocardial injury. Multivariable flexible parametric models were used to characterize the temporal hazard of death, MI, heart failure (HF), and ventricular arrhythmia. RESULTS:372,310 EOCs (218,878 individuals) were included: acute MI (19,052 [5.12%]), acute myocardial injury with CAD (6,928 [1.86%]), acute myocardial injury without CAD (32,231 [8.66%]), chronic myocardial injury (55,056 [14.79%]), and no myocardial injury (259,043 [69.58%]). We observed an early hazard of MI and HF after acute MI and acute myocardial injury with CAD. In contrast, subsequent MI risk was lower and more constant in patients with acute injury without CAD or chronic injury. All patterns of myocardial injury were associated with significantly higher risk of all-cause mortality and ventricular arrhythmia. CONCLUSIONS:Different patterns of myocardial injury were associated with divergent profiles of subsequent cardiac and non-cardiac risk. The therapeutic approach and modifiability of such excess risks require further research.

BACKGROUND:Optimal medical therapy after myocardial infarction with nonobstructive coronary arteries (MINOCA; <50% stenosis) is uncertain. We evaluated variability in discharge prescription of angiotensin-converting enzyme inhibitors / angiotensin receptor blockers (ACEI/ARB) and beta-blockers (BB) to MINOCA patients between hospitals to assess physician equipoise about secondary prevention. METHODS:Patients with MINOCA between 2007-2014 were identified in the NCDR Chest Pain-MI Registry. Those with prior revascularization or missing demographic, angiographic, or medication data were excluded. Analysis was limited to high-volume hospitals with ≥20 MINOCA total discharges. Discharge prescriptions for ACEI/ARB and BB after MINOCA were analyzed for each hospital. Clinical data on left ventricular ejection fraction (LVEF), glomerular filtration rate (GFR), and diabetes mellitus status were extracted to identify other indications for ACEI/ARB or BB. RESULTS:Clinical data were available for 17,849 MINOCA patients, of whom 8,752 (49%) had LVEF <40%, GFR ≤60 mL/min, and/or diabetes. 5,913 patients without one of these indications for ACEI/ARB or BB were discharged from 156 high-volume hospitals. At discharge, ACEI/ARB was prescribed to between 16.0% and 88.8% of MINOCA patients (median 45.6%, IQR 38.0%-56.5%) and BB to between 28.0% and 97.5% (median 74.1%, IQR 64.7%-80.0%). CONCLUSION/CONCLUSIONS:There is marked variability between hospitals in the proportions of patients receiving ACEI/ARB and BB after hospitalization for MINOCA, suggesting clinical equipoise about the routine use of these agents. Randomized clinical trials are necessary to establish the benefit of ACEI/ARB and BB to improve outcomes after MINOCA.