Risk Factors For Perioperative Myocardial Infarction Research Articles

Risk factors for myocardial infarction during carotid endarterectomy in high-risk patients with coronary artery disease

Aim. To determine the value of various risk factors for predicting the myocardial infarction (MI) during carotid endarterectomy in high-risk patients with coronary artery disease (CAD).Material and methods. The single-center cohort prospective study included 204 high-risk patients with CAD who required carotid endarterectomy (CEA). Before surgery, all patients underwent treatment of CAD, and all patients were clinically stabilized. The first step was CEA. Clinical and diagnostic factors associated with the risk of perioperative MI were studied. There were following end points of the study: stroke, MI, death due to MI. The diagnosis of MI was established when there was a combination of an increase in cTn-I troponin above the 99th percentile upper reference limit with electrocardiographic manifestations of myocardial ischemia, or with chest pain or equivalent symptoms consistent with myocardial ischemia.Results. There were no strokes. There were no deaths due to MI. Perioperative MI developed in 8 (3,9%) patients. There were following most significant predictors of perioperative MI: severe impairment of local left ventricular (LV) contractility (hazard ratio (HR), 13,57; 95% confidence interval (CI), 1,427-124,782, p<0,05) and a decrease in left ventricular ejection fraction <50% (HR, 10,909; 95% CI, 1,052-271,229, p<0,05). However, following factors were insignificant for predicting perioperative MI (p>0,05): SYNTAX score, prior cerebrovascular accident, myocardial infarction, insulin-dependent diabetes mellitus, obesity, chronic obstructive pulmonary disease.Conclusion. In high-risk patients with CAD, severe impairment of local LV contractility and global LV systolic dysfunction are the most significant risk factors for perioperative MI during CEA.

A predictive model of perioperative myocardial infarction following elective spine surgery

Myocardial infarction (MI), and its predictive factors, has been an understudied complication following spine operations. The objective was to assess the risk factors for perioperative MI in elective spine surgery patients as a retrospective case control study. Elective spine surgery patients with a perioperative MI were isolated in the NSQIP. The relationship between MI and non-MI spine patients was assessed using chi-squared and independent samples t-tests. Univariate/multivariate analyses assessed predictive factors of MI. Logistic regression with stepwise model selection was employed to create a model to predict MI occurrence. The study included 196,523 elective spine surgery patients (57.1 yrs, 48%F, 30.4 kg/m2), and 436 patients with acute MI (Spine-MI). Incidence of MI did not change from 2010 to 2016 (0.2%–0.3%, p = 0.298). Spine-MI patients underwent more fusions than patients without MI (73.6% vs 58.4%, p < 0.001), with an average of 1.03 levels fused. Spine-MI patients also had significantly more SPO (5.0% vs 1.8%, p < 0.001) and 3CO (0.9% vs 0.2%, p < 0.001), but less decompression-only procedures (26.4% vs 41.6%, p < 0.001). Spine-MI underwent more revisions (5.3% vs 2.9%, p = 0.003), had greater invasiveness scores (3.41 vs 2.73, p < 0.001) and longer operative times (211.6 vs 147.3 min, p < 0.001). Mortality rate for Spine-MI patients was 4.6% versus 0.05% (p < 0.001). Multivariate modeling for Spine-MI predictors yielded an AUC of 83.7%, and included history of diabetes, cardiac arrest and PVD, past blood transfusion, dialysis-dependence, low preoperative platelet count, superficial SSI and days from operation to discharge. A model with good predictive capacity for MI after spine surgery now exists and can aid in risk-stratification of patients, consequently improving preoperative patient counseling and optimization in the peri-operative period.

Myocardial infarction after noncardiac surgery in Sweden: a national, retrospective observational cohort study

BackgroundThe precise incidence of perioperative myocardial infarction (MI) after noncardiac surgery remains unclear. We determined the incidence and risk factors for perioperative MI after noncardiac surgery and the risk of MI and mortality compared with matched non-surgical patients. MethodsPatients >18 yr undergoing noncardiac surgery in 23 Swedish hospitals from 2007 to 2014 were included in this national observational retrospective cohort study. We combined national surgical and outcome databases with Swedeheart, a national quality registry capturing data from patients with acute MI. The primary outcome was incidence of MI within 30 days of surgery. Multivariable logistic regression identified preoperative risk factors associated with MI, including ASA grade, diabetes mellitus, and cardiovascular pathology including previous MI. Standardised incidence rate ratios were calculated. Mortality rates were estimated using Cox proportional hazards. ResultsA total of 1605/400 742 (0.41%) patients (median age: 64 [49–75] yr) had an MI after surgery, which was independently associated with increasing age, comorbidities and higher risk (vascular, thoracic), emergency surgery, or all. The incidence of perioperative MI (per 1000 surgeries) varied from 0.064 (95% confidence interval [CI], 0.02–012) in low-risk patients (ASA physical status 1) to 15.8 (95% CI, 14.9–16.8) among higher risk patients (ASA physical status ≥3, age ≥80 yr, high-risk surgery). Perioperative MI was associated with higher 30-day mortality (adjusted odds ratio: 5.49 [95% 4.76–6.32]). Compared with the non-surgical Swedish population, the perioperative standardised incidence rate ratio was five-fold higher (odds ratio: 5.35 [95% CI: 5.09–5.61]). ConclusionsIn a large Swedish surgical cohort, the incidence of MI within 30 days of noncardiac surgery was 0.41%, chiefly occurring in a small subset of higher risk patients.

Risk Factors Associated with Perioperative Myocardial Infarction in Major Open Vascular Surgery

Among patients undergoing noncardiac surgery, major vascular surgery is associated with a high risk of perioperative myocardial infarction (MI). Currently, there are no perioperative MI risk calculators accounting for intraoperative and postoperative risk factors in vascular surgery patients. We aimed to investigate specific risk factors for perioperative MI after major open vascular surgery to determine which patients are at highest risk of MI and the association of perioperative MI with perioperative transfusion. This statewide, retrospective cohort study analyzed risk factors for perioperative MI in major open vascular surgery between July 2012 and December 2015 using the Michigan Surgical Quality Collaborative, a multicenter quality collaborative. Patients were identified using current procedure terminology codes including open abdominal aortic aneurysm repairs (oAAA), aortobifemoral bypasses (AFB), and lower extremity bypasses (LEB). Rates of myocardial infarction were described for each procedure. A priori, preoperative, intraoperative, and postoperative variables were evaluated using univariate and multivariable statistics after adjusting for intraoperative factors including anesthesia type, intraoperative blood loss, intraoperative transfusion, and intraoperative vasopressor medications. A total of 3,689 patients underwent major open vascular surgery, including 375 oAAA, 392 AFB, and 2,922 LEB procedures. The overall incidence of MI was 2.4%, varying from 1.8% for aortobifemoral bypass, 2.4% for lower extremity bypass, and 3.7% for open abdominal aortic aneurysm repair. Although preoperative risk factors for myocardial infarction included age, American Society of Anesthesiologists score, diabetes, coronary artery disease, congestive heart failure, use of beta blocker, lower preoperative hematocrit, and surgical priority (urgent/emergent cases), after adjusting for intraoperative risk factors, all preoperative risk factors were not significant with the exception of surgical priority. After adjusting for intraoperative factors, only surgical priority (odds ratio [OR]=1.70, 95% confidence interval [CI] [1.01-2.85], P<0.001) and postoperative transfusion (OR=2.65, 95% CI [1.59-4.44], P<0.001) was associated with myocardial infarction, and higher nadir hematocrit was inversely associated with myocardial infarction (OR=0.89, 95% CI [0.85-0.94], P<0.001). Among vascular surgery patients undergoing major open vascular surgery, surgical priority was the only preoperative risk factors independently associated with MI, and only postoperative variables such as nadir hematocrit and postoperative transfusion were associated with MI. This suggests minimizing intraoperative blood loss and prioritizing early intraoperative transfusion may be the potential targets for process improvement.

Abstract 18554: The Association of Diagnostic Criteria for Myocardial Infarction and Peri-Operative Cardiac Risk Factors in Vascular Surgery Patients

Background: The inclusion of cardiac biomarkers and ST-T changes on electrocardiography in the diagnostic criteria for myocardial infarction (MI) has increased the apparent incidence of infarction in the general population. The impact of re-defining MI on the incidence and risk of peri-operative MI is unclear. We evaluate the association between diagnostic criteria changes and incidence of and risk factors for peri-operative MI in vascular surgery patients. Methods: Patients who underwent non-emergent vascular surgery between 2005 and 2011 were identified from the American College of Surgeons’ National Surgical Quality Improvement Program (NSQUIP) multi-center database. In 2005, MI was defined by new Q-waves on electrocardiography. In 2009, the definition included variable electrocardiographic evidence (ST elevation, new left bundle branch block, or new q-waves) or an elevation of cardiac troponin greater than 3 times the upper level of normal. Baseline characteristics were identified, and yearly incidence of MI was determined. Multivariable regression was used to determine risk factors associated with MI according to the old and new definitions. Results: Of 70,811 patients who underwent vascular surgery between 2005 and 2011, 40,017 (57%) were ≥ 70 years old, and 46,206 (65%) were male. High-risk vascular surgery (open abdominal aortic aneurysm repair or aorto-bifemoral bypass) was performed in 7,359 (10%) patients. Peri-operative MI more than tripled from the 2005-2008 to 2009-2011 time periods (1.5% vs. 0.4%; p&lt;0.001). In multivariable analyses, significant risk factors for MI also changed from the earlier to later model (See Table). Conclusions: Re-defining MI increased the apparent incidence of and number of independent risk factors for peri-operative MI. The diagnostic criteria for MI utilized in prior cardiac risk prediction models should be considered when determining risk in patients undergoing non-emergent vascular surgery.

Thirty-day outcome of carotid artery stenting in Chinese patients: a single-center experience

Background Carotid artery stenting (CAS) as a competing treatment modality has had to adhere to limits to gain widespread acceptance in some studies. This study analyzed the clinical data of 1700 consecutive patients after CAS to retrospectively evaluate the 30-day outcome of CAS for internal carotid artery stenosis in a Chinese population. Methods Medical records of 1700 patients who underwent CAS at Xuanwu Hospital affiliated to Capital Medical University between January 2001 and August 2012 were reviewed. Postoperative 30-day complication rates were analyzed and compared with those of other studies. Univariate and multivariate Logistic regression analyses were used to identify factors associated with perioperation myocardial infarction (MI), stroke, and death. Results The overall 30-day rate of MI, stroke, and death after CAS was 2.53%. In univariate analysis, patients who were symptomatic, had a neurological deficit (modified Rankin score (mRS) ≥3; P=0.001), and who were not taking statins experienced a significantly increased rate of MI, stroke, and death (P=0.017). In multivariate Logistic regression analysis, the presence of symptoms (odds ratio (OR)=2.485; 95% confidence interval (CI)=1.267-4.876; P=0.008) and a neurological deficit (mRS ≥3) (OR=3.025; 95% CI=1.353-6.763; P=0.007) were independent risk factors for perioperative MI, stroke, and death. Conclusions According to this single-center experience, CAS may effectively prevent and treat carotid artery stenosis that would otherwise lead to stroke. Being symptomatic and having a neurological deficit (mRS ≥3) increased the risk of perioperative MI, stroke, and death.

Peri-operative cardiac morbidity in kidney transplant recipients: incidence and risk factors.

Renal transplant recipients are known to be at increased risk for developing cardiac disease. In both general and peripheral vascular surgery, pre-operative risk stratification (and intervention when indicated) has decreased the incidence of peri-operative cardiac complications. In this study, we set out to identify subsets of patients at high risk for peri-operative cardiac complications after a renal transplant. We retrospectively reviewed the records of 2694 adult renal transplants performed at the University of Minnesota between January 1, 1985 and December 31, 1998. We determined the incidence of peri-operative (within 30 d post-transplant) cardiac complications, including myocardial infarction (MI). Risk factors for the development of these complications were determined by multivariate analysis. We found 163 peri-operative cardiac complications, for an overall incidence of 6.1%. Specific cardiac complications included MI (n=43, 1.6%), arrhythmia (n=74, 2.7%), angina (n=31, 1.2%), cardiac arrest (n=13, 0.5%), and congestive heart failure (n= 2, 0.1%). By multivariate analysis, significant risk factors for any cardiac complication were age> or =50 yr (relative risk (RR)=3.0, p=0.0001) and pre-transplant cardiac disease (RR=3.3, p=0.0001). Not significant were diabetes mellitus (DM), cadaver donor source, pre-transplant dialysis, a history of smoking, and hypertension. Significant risk factors for peri-operative MI were age> or =50 yr, pre-existing cardiac disease, and DM. Diabetic patients with pre-existing cardiac disease were at especially high risk for peri-operative cardiac events. Patients>50 yr and those with pre-existing cardiac disease, especially if diabetic, are at significantly increased risk for developing peri-operative cardiac complications after a renal transplant. Such patients require aggressive pre-operative investigations, which may include coronary angiography, to decrease the risk of post-transplant complications.