A case-cohort study of postoperative myocardial infarction: impact of anemia and cardioprotective medications

Association of High Mortality With Postoperative Myocardial Infarction After Major Vascular Surgery Despite Use of Evidence-Based Therapies

Importance

Patients undergoing vascular surgery are at high risk of postoperative myocardial infarction (POMI). Postoperative myocardial infarction is independently associated with significant risk of in-hospital mortality.

Objective

To examine the association of patient and procedural characteristics with the risk of POMI after vascular surgery and determine the association of evidence-based therapies with longer-term outcomes.

Design, Setting, and Participants

A retrospective cohort study of prospectively collected data within a statewide quality improvement collaborative database between January 2012 and December 2017. Patient demographics, comorbid conditions, and perioperative medications were captured. Patients were grouped according to occurrence of POMI. Univariate analysis and logistic regression were used to identify factors associated with POMI. The collaborative collects data from private and academic hospitals in Michigan. Patients undergoing major vascular surgery, defined as endovascular aortic aneurysm repair, open abdominal aortic aneurysm, peripheral bypass, carotid endarterectomy, or carotid artery stenting were included. Analysis began December 2018.

Main Outcomes and Measures

The presence of a POMI and 1-year mortality.

Results

Of 26 231 patients identified, 16 989 (65.8%) were men and the overall mean (SD) age was 69.35 (9.89) years. A total of 410 individuals (1.6%) experienced a POMI. Factors associated with higher rates of POMI were age (odds ratio [OR], 1.032 [95% CI, 1.019-1.045]; P < .001), diabetes (OR, 1.514 [95% CI, 1.201-1.907]; P < .001), congestive heart failure (OR, 1.519 [95% CI, 1.163-1.983]; P = .002), valvular disease (OR, 1.447 [95% CI, 1.024-2.046]; P = .04), coronary artery disease (OR, 1.381 [95% CI, 1.058-1.803]; P = .02), and preoperative P2Y12 antagonist use (OR, 1.37 [95% CI, 1.08-1.725]; P = .009). Procedurally, open abdominal aortic aneurysm (OR, 4.53 [95% CI, 2.73-7.517]; P < .001) and peripheral bypass (OR, 2.375 [95% CI, 1.818-3.102]; P < .001) were associated with the highest risk of POMI. After POMI, patients were discharged and received evidence-based therapy with high fidelity, including β-blockade (296 [82.7%]) and antiplatelet therapy (336 [95.7%]). A high portion of patients with POMI were dead at 1 year compared with patients without POMI (113 [37.42%] vs 993 [5.05%]; χ2 = 589.3; P < .001).

Conclusions and Relevance

Despite high rates of discharge with evidence-based therapies, the long-term burden of POMI is substantial, with a high mortality rate in the following year. Patients with diabetes mellitus, coronary artery disease, congestive heart failure, and valvular disease warrant additional consideration in the preoperative period. Further, aggressive strategies to treat patients who experience a POMI are needed to reduce the risk of postoperative mortality.

Adverse cardiac events after vascular surgery are prevalent despite negative results of preoperative stress testing

OBJECTIVE

Cardiac risk assessment is a critical component of vascular disease management before surgical intervention. The predictive risk reduction of a negative cardiac stress test result remains poorly defined. The objective of this study was to compare the incidence of postoperative cardiac events among patients with negative stress test results vs those who did not undergo testing.

METHODS

We reviewed all patients who underwent elective open abdominal aortic aneurysm repair, suprainguinal bypass, endovascular aneurysm repair (EVAR), carotid endarterectomy (CEA), and infrainguinal bypass within the Vascular Study Group of New England from 2003 to 2017. We excluded patients with positive stress test results (n = 3312) and studied two mutually exclusive groups: elective surgery patients with a negative stress test result and elective surgery patients with no stress test (total n = 26,910). The primary outcome was a composite of in-hospital postoperative cardiac events (dysrhythmia, heart attack, heart failure) or death.

RESULTS

A preoperative stress test was obtained in 66.3% of open repairs, 42.8% of suprainguinal bypasses, 37.1% of EVARs, 36.0% of CEAs, and 31.2% of infrainguinal bypasses. The proportion of patients receiving a preoperative stress test varied widely across centers, from 37.1% to 80.0%. The crude odds ratio of in-hospital postoperative cardiac event or death was 1.37 (95% confidence interval [CI], 1.07-1.76) for open repair and 1.52 (CI, 1.13-2.03) for suprainguinal bypass, indicating that patients with negative stress test results before these procedures were 37% and 52% more likely to suffer a postoperative event or die compared with patients selected to proceed directly to surgery without testing. Conversely, the crude odds ratio was 0.92 (CI, 0.66-1.29) for EVAR, 0.92 (CI, 0.70-1.21) for CEA, and 1.13 (CI, 0.90-1.40) for infrainguinal bypass, indicating that patients undergoing these procedures had a similar likelihood of sustaining an event whether they had a negative stress test result or proceeded directly to surgery without a stress test.

CONCLUSIONS

The use of cardiac stress testing before vascular surgery varies widely throughout New England. Whereas patients are often appropriately selected to proceed directly to surgery, a negative preoperative stress test result should not assuage the concern for an adverse outcome as these patients retain a substantial likelihood of cardiac events, especially after large-magnitude procedures.

Association of preoperative anaemia with cardiopulmonary exercise capacity and postoperative outcomes in noncardiac surgery: a substudy of the Measurement of Exercise Tolerance before Surgery (METS) Study

BACKGROUND

Preoperative anaemia is associated with elevated risks of postoperative complications. This association may be explained by confounding related to poor cardiopulmonary fitness. We conducted a pre-specified substudy of the Measurement of Exercise Tolerance before Surgery (METS) study to examine the associations of preoperative haemoglobin concentration with preoperative cardiopulmonary exercise testing performance (peak oxygen consumption, anaerobic threshold) and postoperative complications.

METHODS

The substudy included a nested cross-sectional analysis and nested cohort analysis. In the cross-sectional study (1279 participants), multivariate linear regression modelling was used to determine the adjusted association of haemoglobin concentration with peak oxygen consumption and anaerobic threshold. In the nested cohort study (1256 participants), multivariable logistic regression modelling was used to determine the adjusted association of haemoglobin concentration, peak oxygen consumption, and anaerobic threshold with the primary endpoint (composite outcome of death, cardiovascular complications, acute kidney injury, or surgical site infection) and secondary endpoint (moderate or severe complications).

RESULTS

Haemoglobin concentration explained 3.8% of the variation in peak oxygen consumption and anaerobic threshold (P<0.001). Although not associated with the primary endpoint, haemoglobin concentration was associated with moderate or severe complications after adjustment for peak oxygen consumption (odds ratio=0.86 per 10 g L^-1 increase; 95% confidence interval, 0.77-0.96) or anaerobic threshold (odds ratio=0.86; 95% confidence interval, 0.77-0.97). Lower peak oxygen consumption was associated with moderate or severe complications without effect modification by haemoglobin concentration (P=0.12).

CONCLUSION

Haemoglobin concentration explains a small proportion of variation in exercise capacity. Both anaemia and poor functional capacity are associated with postoperative complications and may therefore be modifiable targets for preoperative optimisation.

Clinical utility of the revised cardiac risk index in older Chinese patients with known coronary artery disease

Objectives

The revised Cardiac Risk Index (RCRI) is the most widely used risk prediction tool for postoperative cardiac adverse events. We aim to explore the predictive ability of the RCRI in older Chinese patients with coronary artery disease (CAD) undergoing noncardiac surgery, which has not been previously evaluated.

Methods

We performed a multicenter, prospective study. We enrolled a total of 1,202 patients, aged >60 years, with a history of CAD who underwent noncardiac surgery. Perioperative data were extracted from an electronic database. The primary end point was defined as an occurrence of a postoperative major cardiac event (PoMCE) within 30 days. Logistic regression analysis was performed to evaluate the performance of the RCRI. A modified RCRI was created and compared with the original RCRI with regard to its ability to predict postoperative cardiac events.

Results

Of the enrolled patients, 4.3% experienced PoMCE. Most components of the RCRI were not predictive of postoperative cardiac events with the exception of insulin-dependent diabetes mellitus (odds ratio =2.38, 95% CI: 1.11-5.11; P=0.03). The RCRI performed no better than chance (area under the curve =0.53; 95% CI: 0.45-0.61) in identifying patients' cardiac risk. The modified score had a higher discriminatory ability toward PoMCE (c index, 0.69 versus 0.53; P<0.01).

Conclusion

The original RCRI shows poor predictive ability in Chinese patients with CAD undergoing noncardiac surgery.

The Clinical Impact of Cardiology Consultation Prior to Major Vascular Surgery

OBJECTIVE

To understand statewide variation in preoperative cardiology consultation prior to major vascular surgery and to determine whether consultation was associated with differences in perioperative myocardial infarction (poMI).

SUMMARY BACKGROUND DATA

Medical consultation prior to major vascular surgery is obtained to reduce perioperative risk. Despite perceived benefit of preoperative consultation, evidence is lacking specifically for major vascular surgery on the effect of preoperative cardiac consultation.

METHODS

Patient and clinical data were obtained from a statewide vascular surgery registry between January 2012 and December 2014. Patients were risk stratified by revised cardiac risk index category and compared poMI between patients who did or did not receive a preoperative cardiology consultation. We then used logistic regression analysis to compare the rate of poMI across hospitals grouped into quartiles by rate of preoperative cardiology consultation.

RESULTS

Our study population comprised 5191 patients undergoing open peripheral arterial bypass (n = 3037), open abdominal aortic aneurysm repair (n = 332), or endovascular aneurysm repair (n = 1822) at 29 hospitals. At the patient level, after risk-stratification by revised cardiac risk index category, there was no association between cardiac consultation and poMI. At the hospital level, preoperative cardiac consultation varied substantially between hospitals (6.9%-87.5%, P <0.001). High preoperative consulting hospitals (rate >66%) had a reduction in poMI (OR, 0.52; confidence interval: 0.28-0.98; P <0.05) compared with all other hospitals. These hospitals also had a statistically greater consultation rate with a variety of medical specialties.

CONCLUSIONS

Preoperative cardiology consultation for vascular surgery varies greatly between institutions, and does not appear to impact poMI at the patient level. However, reduction of poMI was noted at the hospitals with the highest rate of preoperative cardiology consultation as well as a variety of medical services, suggesting that other hospital culture effects play a role.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Smoking, Gender, and Overweight Are Important Influencing Factors on Monocytic HLA-DR before and after Major Cancer Surgery

Background

Monocytic human leukocyte antigen D related (mHLA-DR) is essential for antigen-presentation. Downregulation of mHLA-DR emerged as a general biomarker of impaired immunity seen in patients with sepsis and pneumonia and after major surgery. Influencing factors of mHLA-DR such as age, overweight, diabetes, smoking, and gender remain unclear.

Methods

We analyzed 20 patients after esophageal or pancreatic resection of a prospective, randomized, placebo-controlled, double-blind trial (placebo group). mHLA-DR was determined from day of surgery (od) until postoperative day (pod) 5. Statistical analyses were performed using multivariate generalized estimating equation analyses (GEE), nonparametric multivariate analysis of longitudinal data, and univariate post hoc nonparametric Mann–Whitney tests.

Results

In GEE, smoking and gender were confirmed as significant influencing factors over time. Univariate analyses of mHLA-DR between smokers and nonsmokers showed lower preoperative levels (p = 0.010) and a trend towards lower levels on pod5 (p = 0.056) in smokers. Lower mHLA-DR was seen in men on pod3 (p = 0.038) and on pod5 (p = 0.026). Overweight patients (BMI > 25 kg/m²) had lower levels of mHLA-DR on pod3 (p = 0.039) and pod4 (p = 0.047).

Conclusion

Smoking is an important influencing factor on pre- and postoperative immune function while postoperative immune function was influenced by gender and overweight. Clinical trial registered with ISRCTN27114642.

Combined Hyperactive Dysfunction Syndrome of the Cranial Nerves: A Retrospective Systematic Study of Clinical Characteristics in 44 Patients

BACKGROUND

Combined hyperactive dysfunction syndrome (HDS) is defined as the combination symptoms arising from overactivity in cranial nerves, specifically, trigeminal neuralgia (TN), hemifacial spasm (HFS), and glossopharyngeal neuralgia (GPN), without an obvious explanatory structural lesion. This study retrospectively analyzes the clinical characteristics of combined HDS treated with microvascular decompression (MVD) in a single institution.

METHODS

A total of 1450 patients with HDS were treated with MVD in our department during a 10-year period, among which 44 cases of combined HDS were identified. Clinical records and follow-ups were reviewed.

RESULTS

Combined HDS comprised 3.03% (44/1450) of all HDS in our series, with female predominance compared with single HDS (P = 0.002), including combined TN-HFS (14 cases), combined TN-GPN (26 cases), bilateral TN (2 cases), and combined TN-HFS-GPN (2 cases). The average age at diagnosis of patients with combined HDS (60.9 years) was significantly older than that of patients with single HDS (53.5 years) (P = 0.035). Hypertension was closely associated with the prevalence of combined HDS compared with single HDS (P = 0.009). The curative rate was 97.7% (43/44) after MVD, and the recurrence rate was 3.33%. The incidence rates of postoperative cardiac, pulmonary, thromboembolic, and delirium complications were higher in combined HDS than in single HDS (P < 0.05).

CONCLUSIONS

Combined HDS is a rarely occurring syndrome usually observed in older females, and the most common types are combined TN-GPN and combined TN-HFS. Age and gender seemed to be causes for developing combined HDS, and MVD shows potential as a favorable treatment choice.