Obesity paradox and perioperative myocardial infarction/injury in non-cardiac surgery.

BACKGROUND: The impact of obesity on the incidence of perioperative myocardial infarction/injury (PMI) and mortality following non-cardiac surgery is not well understood. METHODS: We performed a prospective diagnostic study enrolling consecutive patients undergoing non-cardiac surgery, who were considered at increased cardiovascular risk. All patients were screened for PMI, defined as an absolute increase from preoperative to postoperative sensitive/high-sensitivity cardiac troponin T (hs-cTnT) concentrations. The body mass index (BMI) was classified according to the WHO classification (underweight< 18 kg/m2, normal weight 18-24.9 kg/m2, overweight 25-29.9 kg/m2, obesity class I 30-34.9 kg/m2, obesity class II 35-39.9 kg/m2, obesity class III > 40 kg/m2). The incidence of PMI and all-cause mortality at 365 days, both stratified according to BMI. RESULTS: We enrolled 4277 patients who had undergone 5413 surgeries. The median BMI was 26 kg/m2 (interquartile range 23-30 kg/m2). Incidence of PMI showed a non-linear relationship with BMI and ranged from 12% (95% CI 9-14%) in obesity class I to 19% (95% CI 17-42%) in the underweight group. This was confirmed in multivariable analysis with obesity class I. showing the lowest risk (adjusted OR 0.64; 95% CI 0.49-0.83) for developing PMI. Mortality at 365 days was lower in all obesity groups compared to patients with normal body weight (e.g., unadjusted OR 0.54 (95% CI 0.39-0.73) and adjusted OR 0.52 (95% CI 0.38-0.71) in obesity class I). CONCLUSION: Obesity class I was associated with a lower incidence of PMI, and obesity in general was associated with a lower all-cause mortality at 365 days.

Daytime variation of perioperative myocardial injury in non-cardiac surgery and effect on outcome.

OBJECTIVE: Recently, daytime variation in perioperative myocardial injury (PMI) has been observed in patients undergoing cardiac surgery. We aim at investigating whether daytime variation also occurs in patients undergoing non-cardiac surgery. METHODS: In a prospective diagnostic study, we evaluated the presence of daytime variation in PMI in patients at increased cardiovascular risk undergoing non-cardiac surgery, as well as its possible impact on the incidence of acute myocardial infarction (AMI), and death during 1-year follow-up in a propensity score-matched cohort. PMI was defined as an absolute increase in high-sensitivity cardiac troponin T (hs-cTnT) concentration of ≥14 ng/L from preoperative to postoperative measurements. RESULTS: Of 1641 patients, propensity score matching defined 630 with similar baseline characteristics, half undergoing non-cardiac surgery in the morning (starting from 8:00 to 11:00) and half in the afternoon (starting from 14:00 to 17:00). There was no difference in PMI incidence between both groups (morning: 50, 15.8% (95% CI 12.3 to 20.3); afternoon: 52, 16.4% (95% CI 12.7 to 20.9), p=0.94), nor if analysing hs-cTnT release as a quantitative variable (median morning group: 3 ng/L (95% CI 1 to 7 ng/L); median afternoon group: 2 ng/L (95% CI 0 to 7 ng/L; p=0.16). During 1-year follow-up, the incidence of AMI was 1.2% (95% CI 0.4% to 3.2%) among morning surgeries versus 4.1% (95% CI 2.3% to 6.9%) among the afternoon surgeries (corrected HR for afternoon surgery 3.44, bootstrapped 95% CI 1.33 to 10.49, p log-rank=0.03), whereas no difference in mortality emerged (p=0.70). CONCLUSIONS: Although there is no daytime variation in PMI in patients undergoing non-cardiac surgery, the incidence of AMI during follow-up is increased in afternoon surgeries and requires further study. CLINICAL TRIAL REGISTRATION: NCT02573532;Results.

Perioperative Myocardial Injury After Noncardiac Surgery: Incidence, Mortality, and Characterization.

BACKGROUND: Perioperative myocardial injury (PMI) seems to be a contributor to mortality after noncardiac surgery. Because the vast majority of PMIs are asymptomatic, PMI usually is missed in the absence of systematic screening. METHODS: We performed a prospective diagnostic study enrolling consecutive patients undergoing noncardiac surgery who had a planned postoperative stay of ≥24 hours and were considered at increased cardiovascular risk. All patients received a systematic screening using serial measurements of high-sensitivity cardiac troponin T in clinical routine. PMI was defined as an absolute high-sensitivity cardiac troponin T increase of ≥14 ng/L from preoperative to postoperative measurements. Furthermore, mortality was compared among patients with PMI not fulfilling additional criteria (ischemic symptoms, new ECG changes, or imaging evidence of loss of viable myocardium) required for the diagnosis of spontaneous acute myocardial infarction versus those that did. RESULTS: From 2014 to 2015 we included 2018 consecutive patients undergoing 2546 surgeries. Patients had a median age of 74 years and 42% were women. PMI occurred after 397 of 2546 surgeries (16%; 95% confidence interval, 14%-17%) and was accompanied by typical chest pain in 24 of 397 patients (6%) and any ischemic symptoms in 72 of 397 (18%). Crude 30-day mortality was 8.9% (95% confidence interval [CI], 5.7-12.0) in patients with PMI versus 1.5% (95% CI, 0.9-2.0) in patients without PMI (P<0.001). Multivariable regression analysis showed an adjusted hazard ratio of 2.7 (95% CI, 1.5-4.8) for 30-day mortality. The difference was retained at 1 year with mortality rates of 22.5% (95% CI, 17.6-27.4) versus 9.3% (95% CI, 7.9-10.7). Thirty-day mortality was comparable among patients with PMI not fulfilling any other of the additional criteria required for spontaneous acute myocardial infarction (280/397, 71%) versus those with at least 1 additional criterion (10.4%; 95% CI, 6.7-15.7, versus 8.7%; 95% CI, 4.2-16.7; P=0.684). CONCLUSIONS: PMI is a common complication after noncardiac surgery and, despite early detection during routine clinical screening, is associated with substantial short- and long-term mortality. Mortality seems comparable in patients with PMI not fulfilling any other of the additional criteria required for spontaneous acute myocardial infarction versus those patients who do. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02573532.

Prediction of major cardiac events after vascular surgery.

OBJECTIVE: Predicting cardiac events is essential to provide patients with the best medical care and to assess the risk-benefit ratio of surgical procedures. The aim of our study was to evaluate the performance of the Revised Cardiac Risk Index (Lee) and the Vascular Study Group of New England Cardiac Risk Index (VSG) scores for the prediction of major cardiac events in unselected patients undergoing arterial surgery and to determine whether the inclusion of additional risk factors improved their accuracy. METHODS: The study prospectively enrolled 954 consecutive patients undergoing arterial vascular surgery, and the Lee and VSG scores were calculated. Receiver operating characteristic curves for each cardiac risk score were constructed and the areas under the curve (AUCs) compared. Two logistic regression models were done to determine new variables related to the occurrence of major cardiac events (myocardial infarction, heart failure, arrhythmias, and cardiac arrest). RESULTS: Cardiac events occurred in 120 (12.6%) patients. Both scores underestimated the rate of cardiac events across all risk strata. The VSG score had AUC of 0.63 (95% confidence interval [CI], 0.58-0.68), which was higher than the AUC of the Lee score (0.58; 95% CI, 0.52-0.63; P = .03). Addition of preoperative anemia significantly improved the accuracy of the Lee score to an AUC of 0.61 (95% CI, 0.58-0.67; P = .002) but not that of the VSG score. CONCLUSIONS: The Lee and VSG scores have low accuracy and underestimate the risk of major perioperative cardiac events in unselected patients undergoing vascular surgery. The Lee score's accuracy can be increased by adding preoperative anemia. Underestimation of major cardiac complications may lead to incorrect risk-benefit assessments regarding the planned operation.

Comparison of endothelium-dependent and -independent vasomotor response after abluminal biodegradable polymer biolimus-eluting stent and persistent polymer everolimus-eluting stent implantation (COMPARE-IT).

BACKGROUND: Drug-eluting stents (DES) have been associated with local endothelial dysfunction in the segments proximal and distal to the stent (peristent segments) and increased thrombotic risk in long term follow-up. Little data exists on endothelial function post-implantation of new DES with biodegradable polymer. The aim of our study was to compare the local endothelial function assessed by exercise induced coronary vasomotion after implantation of a biolimus A9-eluting stent with biodegradable polymer (BES) with an everolimus-eluting stent with durable polymer (EES). METHODS: Coronary vasomotion was evaluated with quantitative coronary angiography at rest and during supine bicycle exercise in nine patients with EES and thirteen patients with BES, 16 months after stent implantation. Mean luminal diameter of the stent, peristent segments, and of a control vessel were determined at rest, during exercise, and after the administration of nitroglycerine. RESULTS: The control vessel showed exercise-induced vasodilatation in both groups (EES: +6.4±5.5%, p=0.07; BES: +7.8±10.1%, p=0.07). Vasomotion in the stented vessel segment was abolished. There was exercise-induced vasoconstriction in both groups in the segments proximal (EES: -9.6±4.5%; p=0.03; BES: -4.3±5.4%, p=0.02) and distal to the stent (EES: -3.2±9.3%; p=0.41, BES -8.6±8.0%, p<0.01). Sublingual nitroglycerin was associated with maximal vasodilatation of the peristent segments in both groups. CONCLUSION: Alike DES with durable polymer, stents with a biodegradable polymer are associated with exercise-induced paradoxical coronary vasoconstriction of the peristent segments. This data suggests that endothelial dysfunction after DES implantation is not primarily caused by the durability of the polymer coating.

Heart failure therapy-induced early ST2 changes may offer long-term therapy guidance.

BACKGROUND: Biomarkers may help to monitor and tailor treatment in patients with acute heart failure (AHF). METHODS AND RESULTS: Levels of ST2, a novel biomarker integrating hypervolemic cardiac strain and proinflammatory signals, were measured at presentation to the emergency department (ED) and after 48 hours in 207 patients with AHF. Patients were stratified according to their early ST2 response (responders: ST2 decrease ≥25%; nonresponders: ST2 decrease <25%) and beta-blocker, renin-angiotensin-aldosterone system (RAAS) blockade, or diuretic treatment status at hospital discharge. We assessed the utility of ST2 levels and its changes to predict long-term mortality and the interaction between ST2 levels, treatment at discharge, and 1-year mortality. ST2 levels were higher in nonsurvivors than in survivors (median 108 vs 69 ng/mL; P < .01) and decreased significantly during the 1st 48 hours (median decrease 33%). ST2 decrease was less in nonsurvivors compared with survivors (median -25% vs -42%; P < .01). In Cox regression, early ST2 changes independently predicted 1-year mortality (hazard ratio 1.07 for every increase of 10%; P = .02). RAAS blockers at discharge were associated with survival independently from ST2 response, whereas the association of beta-blockers with survival differed markedly according to ST2 response, with beneficial effects restricted to ST2 nonresponders (P interaction = .04). A similar, albeit nonsignificant, trend was observed for diuretics (P interaction = .11). CONCLUSIONS: ED and serial ST2 measurements are independent predictors of 1-year mortality in AHF.