Protecting the heart with cardiac medication in patients with left ventricular dysfunction undergoing major noncardiac vascular surgery

Patients with left ventricular dysfunction who are undergoing major noncardiac vascular surgery are at increased risk of adverse postoperative events. We sought to evaluate whether perioperative medication use, including angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, statins, and aspirin, was associated with a reduced incidence of postoperative in-hospital mortality in these high-risk patients. The study enrolled 511 patients with left ventricular dysfunction (left ventricular ejection fraction <30%) who were undergoing major noncardiac vascular surgery. Cardiac risk factors and medication use were noted before surgery. Preoperative dobutamine stress echocardiography (DSE) was performed to identify patients with stress-induced myocardial ischemia. The end point was postoperative in-hospital mortality. Univariate and multivariate logistic regression analyses were performed to evaluate the relation between perioperative medication use and mortality. The mean age of the study population was 64 +/- 11 years, and 75% were men. Perioperative use of ACE inhibitors, beta-blockers, statins, and aspirin was recorded in 215 (48%), 139 (27%), 107 (21%), and 125 patients (24%), respectively. Stress-induced myocardial ischemia occurred in 82 patients (16%). Sixty-four patients (13%) died. Perioperative use of ACE inhibitors (odds ratio [OR], 0.33; 95% confidence interval [CI], 0.12-0.91), beta-blockers (OR, 0.03; 95% CI, 0.01-0.26), statins (OR, 0.06; 95% CI, 0.01-0.53), and aspirin (OR, 0.13; 95% CI, 0.03-0.55), was significantly associated with a reduced incidence of mortality, after adjusting for cardiac risk factors and DSE results. In conclusion, the present study showed that the perioperative use of ACE inhibitors, beta-blockers, statins, and aspirin is independently associated with a reduced incidence of in-hospital mortality in patients with left ventricular dysfunction who are undergoing major noncardiac vascular surgery.     

Which stress test is superior for perioperative cardiac risk stratification in patients undergoing major vascular surgery?

OBJECTIVE: to compare the additional prognostic value of Dobutamine Stress Echocardiography (DSE), Dipyridamole Stress Echocardiography (DiSE) and Perfusion Scintigraphy (DTS) on clinical risk factors in patients undergoing major vascular surgery. DESIGN: retrospective analysis. MATERIALS: 2204 consecutive patients who underwent DSE (n=1093), DiSE (n=394), or DTS (n=717) testing before major vascular surgery were studied. METHODS: primary endpoint was a composite of cardiac death and non-fatal myocardial infarction (MI). Logistic regression analysis was performed to evaluate the relation between cardiac risk factors, stress test results and the incidence of the composite endpoint. RESULTS: there were 138 patients (6.3%) with cardiac death or MI. Patients with 0, 1-2, and 3 or more risk factors experienced respectively 3.0, 5.7 and 17.4% cardiac events. We found no statistically significant difference in the predictive value of a positive test result for DiSE and DSE (Odds ratio (OR) of 37.1 [95% CI, 8.1-170.1] vs 9.6 [95% CI, 4.9-18.4]; p=0.12), whereas a positive test result for DTS had significantly lower prognostic value (OR=1.95 [95% CI, 1.2-3.2]). CONCLUSION: a result of stress echocardiography effectively stratified patients into low- and high-risk groups for cardiac complications, irrespective of clinical risk profile. In contrast, the prognostic value of DTS results was more likely to be dependent on patients' clinical risk profile.     

Beta-blockers improve in-hospital and long-term survival in patients with severe left ventricular dysfunction undergoing major vascular surgery.

OBJECTIVES: To study whether beta-blockers reduce in-hospital and long-term mortality in patients with severe left ventricular dysfunction (LVD) undergoing major vascular surgery. DESIGN: Observational cohort study. MATERIALS: Five hundred and eleven patients with severe LVD (ejection fraction<30%) undergoing major non-cardiac vascular surgery. METHODS: In all patients, cardiac risk factors, medication (including beta-blockers), and dobutamine stress echocardiography (DSE) results were noted prior to surgery. DSE was evaluated for rest and stress-induced new wall motion abnormalities. Endpoint was in-hospital and long-term mortality. Propensity scores for beta-blockers were calculated and regression models were used to analyse the relation between beta-blockers and mortality. RESULTS: Mean age was 64+/-11 years and 383 patients (75%) were male. 139 patients (27%) used beta-blockers. Stress-induced ischemia occurred in 82 patients (16%). Median follow-up was 7 years (interquartile range: 3-10). In-hospital and long-term mortality was observed in 64 (13%) and 171 (33%) patients, respectively. After adjusting for clinical variables, DSE results and propensity scores, beta-blockers were significantly associated with reduced in-hospital and long-term mortality (OR: 0.18, 95% CI: 0.04-0.74 and HR: 0.38, 95% CI: 0.22-0.65, respectively). CONCLUSION: In patients with severe LVD undergoing major vascular surgery, the use of beta-blockers is associated with a reduced incidence of in-hospital and long-term postoperative mortality.     

Increase of 1-year mortality after perioperative beta-blocker withdrawal in endovascular and vascular surgery patients.

OBJECTIVES: To assess the relation between beta-blocker use, underlying cardiac risk, and 1-year outcome in vascular surgery patients, including the effect of beta-blocker withdrawal. DESIGN: Prospective survey. MATERIALS: 711 consecutive peripheral vascular surgery patients from 11 hospitals in the Netherlands between May and December 2004. METHODS: Patients were evaluated for cardiac risk factors, beta-blocker use and 1-year mortality. Low and high risk was defined according to the Revised Cardiac Risk Index. Propensity scores for the likelihood of beta-blocker use were calculated and regression models were used to study the relation between beta-blocker use and mortality. RESULTS: 285 patients (40%) received beta-blockers throughout the perioperative period (continuous users). Only 52% of the 281 high risk patients received continuous beta-blocker therapy. Beta-blocker therapy was started in 29 and stopped in 21 patients, respectively. One-year mortality was 11%. After adjustment for potential confounders and the propensity of its use, continuous beta-blocker use remained significantly associated with a lower 1-year mortality compared to non-users (HR=0.4; 95%CI=0.2-0.7). In contrast, beta-blocker withdrawal was associated with an increased risk of 1-year mortality compared to non-users (HR=2.7; 95%CI=1.2-5.9). CONCLUSIONS: We demonstrated an under-use of beta-blockers in vascular surgery patients, even in high-risk patients. Perioperative beta-blocker use was independently associated with a lower risk of 1-year mortality compared to non-use, while perioperative withdrawal of beta-blocker therapy was associated with a higher 1-year mortality.     

Perioperative beta-blocker and statin therapy

PURPOSE OF REVIEW: Perioperative beta-blockade and statin therapy have been advocated to reduce cardiac risk of noncardiac surgery. This review evaluates recent articles published on the cardioprotective effects of perioperative therapy with these medications. RECENT FINDINGS: Initial studies evaluating beta-blocker therapy during the perioperative period suggested that beta-blockers may be beneficial in reducing cardiac deaths and myocardial infarctions. Later studies and recent meta-analyses, however, are less favorable and suggest that beta-blockers may be associated with increased incidence of bradycardia and hypotension. One randomized trial and several cohort studies have found a significant reduction in cardiovascular complications with perioperative statin therapy. Additionally, statin withdrawal is associated with increased postoperative cardiac risk. SUMMARY: Based upon the available evidence and guidelines, patients currently taking beta-blockers should continue these agents. Patients undergoing vascular surgery who are at high cardiac risk should also take beta-blockers. The question remains regarding the best protocol to initiate perioperative beta-blockade. Statins should be continued in patients already taking these agents prior to surgery. The optimal duration and time of initiation of statin therapy remains unclear.     

Delirium following vascular surgery: increased incidence with preoperative β-blocker administration

Purpose

To determine if there is an association between perioperative administration of beta-blockers and postoperative delirium in patients undergoing vascular surgery.

Methods

After Institutional Review Board approval, data were retrospectively collected on patients who underwent vascular surgery in an academic hospital during the period January 2006 to January 2007. Patients with preoperative altered level of consciousness, carotid endarterectomy, or discharge within 24 h of surgery were excluded from the study. Identification of delirium was based on evaluation of the level of consciousness with the NEECHAM Confusion Scale and/or a chart-based instrument for delirium. Multivariable logistic regression analysis was used to identify independent perioperative predictors of postoperative delirium. Beta-blockers were tested for a potential effect.

Results

The incidence of postoperative delirium was 128/582 (22%). Independent predictors included age (OR 1.04, 95% CI [1.02–1.07]), history of cerebrovascular accident/transient ischemic attack (OR 2.64, 95% CI [1.57–4.55]), and depression (OR 3.56, 95% CI [1.53–8.28]). Open aortic reconstruction was associated with an OR of 5.34, 95% CI (2.54–11.2) and amputation with an OR of 4.66, 95% CI (1.96–11.09). Preoperative beta-blocker administration increased the odds of postoperative delirium 2.06 times (95% CI [1.18–3.6]). Statin administration reduced the odds of delirium by 44% (95% CI [0.37–0.88]). The model was reliable (Hosmer–Lemeshow test, P = 0.72) and discriminative (area under the receiver operating characteristic [ROC] curve = 0.729).

Conclusions

Preoperative administration of beta-blockers is associated with an increased risk of postoperative delirium after vascular surgery. Conversely, preoperative statin administration is associated with a lower risk of postoperative delirium. A randomized prospective controlled trial is required to validate these findings.     

Risk factors and clinical impact of postoperative symptomatic venous thromboembolism

BACKGROUND: Although common risk factors for venous thromboembolism (VTE) are well known, little data exist concerning the clinical impact of VTE in postoperative patients outside of controlled studies. This study evaluated prospective perioperative demographic and clinical variables associated with occurrence of postoperative symptomatic VTE. METHODS: Demographic and clinical data were collected on surgical patients undergoing nine common general, vascular, and orthopedic operations presenting to the Veterans Health Administration Hospitals between 1996 and 2001 as part of the National Surgical Quality Improvement Program (NSQIP). The association between covariates and the incidence of postoperative symptomatic VTE (includes deep venous thrombosis and pulmonary embolism) was assessed using bivariable and multivariable regression. RESULTS: Complete demographic and clinical information for analysis were available for 75,771 patients. The mean patient age was 65 years, and 96.6% were men. Major comorbidities included diabetes mellitus (DM), 25%; chronic obstructive pulmonary disease (COPD), 18.3%; and congestive heart failure (CHF), 3.9%. Symptomatic VTE was diagnosed in 805 patients (0.68%), varied significantly with procedure (0.14% for carotid endarterectomy vs 1.34% for total hip arthroplasty), and was associated with increased 30-day mortality (16.9% vs 4.4%, P < .0001). The incidence of VTE did not decline substantially between 1996 and 2001 (0.72% vs 0.68%). Preoperative factors associated with symptomatic VTE were older age, male gender, corticosteroid use, COPD, recent weight loss, disseminated cancer, low albumin, and low hematocrit (all P < .01) but not DM. Postoperative factors associated with VTE were myocardial infarction (MI), blood transfusion (>4 units), coma, pneumonia, and urinary tract infection (UTI), whereas those with hemodialysis-dependent renal failure were less likely to experience VTE (all P < .01). In multivariable analysis, adjusting for age and the variables significant by bivariable analysis, the strongest positive predictors of symptomatic VTE included UTI (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3 to 2.5), acute renal insufficiency (OR, 1.9; 95% CI, 1.1 to 3.2), postoperative transfusion (OR, 2.3; 95% CI, 1.4 to 3.7), perioperative MI (OR, 2.4; 95% CI, 1.5 to 3.9), and pneumonia (OR, 2.7; 95% CI, 2.1 to 3.5). In contrast, hemodialysis (OR, 0.3; 95% CI, 0.07 to 0.71), DM (OR, 0.75; 95% CI, 0.61 to 0.93), and higher preoperative albumin levels (OR, 0.8; 95% CI, 0.74 to 0.96, per mg/dL change) were protective from symptomatic VTE. CONCLUSIONS: Although the overall incidence of symptomatic VTE is low in surgical patients, it is associated with significantly increased 30-day mortality. In addition to previously recognized risk factors, patients who have postoperative complications of an infectious nature, bleeding, or MI are at particular risk.     

Patients undergoing infrainguinal bypass to treat atherosclerotic vascular disease are underprescribed cardioprotective medications: effect on graft patency, limb salvage, and mortality

INTRODUCTION: Established American Heart Association guidelines recommend the use of statin drugs, angiotensin converting enzyme (ACE) inhibitors, and antiplatelet agents in patients with systemic atherosclerosis, such as those undergoing operative intervention to treat peripheral atherosclerotic disease. Many of these patients have not received treatment of coronary heart disease and have not been prescribed these medications. Whether statin drugs and ACE inhibitors confer an improvement in graft patency, limb salvage, and operative mortality is unknown. METHODS: Consecutive patients who underwent infrainguinal bypass between 1997 and 2002 were evaluated for demographic data, comorbid disease, medication use, as well as cumulative graft patency, limb salvage, and mortality. Univariate, multivariate logistical regression, and Kaplan-Meier analyses were performed. P <.05 was considered significant. RESULTS: Two hundred ninety-three patients (mean age, 64 years; 67% men) underwent 338 infrainguinal bypass procedures with autologous vein (n = 218), prosthetic grafts (n = 88), or composite prosthetic-vein grafts (n = 32). Limb salvage was the operative indication in 75% of procedures. Coexisting diseases included hypertension (70%), diabetes (52%), hyperlipidemia (37%), coronary heart disease (51%), congestive heart failure (14%), and active tobacco use (30%). Statin drugs were taken by 56% of patients, ACE inhibitors by 54% of patients, and antiplatelet agents or warfarin sodium (Coumadin) by 93% of patients. Postoperative graft surveillance was done in 39% of patients. Cumulative graft patency was 73%, limb salvage was 85%, and mortality was 9%, with a mean follow-up of 17 months.Factors independently associated with increased graft patency included statin drug use (odds ratio [OR], 3.7; 95% confidence interval [CI], 2.1-6.4), male sex (OR, 2.8; 95% CI, 1.6-5.0), and graft surveillance (OR, 2.4; 95% CI, 1.3-4.5). Factors associated with decreased amputation rate were statin drug use (OR, 0.34; 95% CI, 6.15-0.77) and graft surveillance (OR, 0.23; 95% CI, 6.1-0.63). Factors associated with decreased mortality included graft surveillance (OR, 0.18; 95% CI, 0.1-0.56), whereas congestive heart failure (OR, 6.5; 95% CI, 2.5-17) and hemodialysis-dependent renal failure (OR, 29; 95% CI, 6.1-140) were associated with increased mortality. Kaplan-Meier analysis showed that only ACE inhibitors were associated with lower mortality (P =.05) CONCLUSIONS: Patients undergoing infrainguinal bypass are undertreated with respect to cardioprotective medications. ACE inhibitor use is associated with lower mortality, and statin drug use is associated with improved graft patency and limb salvage. Institution of consensus guidelines concerning these medications should be considered by all vascular specialists, including vascular surgeons.     

Coronary angiography and failure to rescue after postoperative myocardial infarction in patients with coronary stents undergoing noncardiac surgery

Background

We evaluated coronary angiography use among patients with coronary stents suffering postoperative myocardial infarction (MI) and the association with mortality.

Methods

Patients with prior coronary stenting who underwent inpatient noncardiac surgery in Veterans Affairs hospitals between 2000 and 2012 and experienced postoperative MI were identified. Predictors of 30-day post-MI mortality were evaluated.

Results

Following 12,096 operations, 353 (2.9%) patients had postoperative MI and 58 (16.4%) died. Post-MI coronary angiography was performed in 103 (29.2%) patients. Coronary angiography was not associated with 30-day mortality (odds ratio [OR]: .70, 95% CI: .35–1.42). Instead, 30-day mortality was predicted by revised cardiac risk index ≥3 (OR 1.91, 95% CI: 1.04–3.50) and prior bare metal stent (OR 2.12, 95% CI: 1.04–4.33).

Conclusions

Less than one-third of patients with coronary stents suffering postoperative MI underwent coronary angiography. Significant predictors of mortality were higher revised cardiac risk index and prior bare metal stent. These findings highlight the importance of comorbidities in predicting mortality following postoperative MI.     

The Role of Perioperative Statin Use in the Prevention of Delirium After Total Knee Replacement Under Spinal Anesthesia

Background

The relationship between statin use and incidence of postoperative delirium (POD) is controversial. We investigated the association between perioperative statin use and occurrence of delirium after total knee arthroplasty (TKA) under spinal anesthesia.

The effect of statin medications on perioperative and long-term outcomes following carotid endarterectomy or stenting

Statins belong to a class of drugs known to inhibit 3-hydroxy 3-methylglutaryl coenzyme A reductase, and block hepatic cholesterol synthesis. Since the initial statin was approved by the Food and Drug Administration in 1987, these agents quickly became the gold standard for treatment of hypercholesterolemia. Effective lipid-lowering has been found to improve the long-term prognosis of patients with coronary artery disease. In addition, statins have also been found to be highly effective in primary and secondary stroke prevention among medically managed patients with cardiovascular disease, and it appears that this benefit is largely due to the non-cholesterol-lowering, so-called pleiotropic, effects of statins. During the past decade, agents such as beta-blockers, aspirin, or other antiplatelet medications have proven to reduce the incidence of adverse postoperative outcomes among vascular surgical patients, and have rightfully assumed a place in our overall therapeutic armamentarium. There is growing evidence that statins may be especially effective in reducing cardiovascular morbidity and improving outcomes after major vascular surgery. A recent study from Johns Hopkins Hospital demonstrated a threefold reduction in the rate of perioperative stroke (P < .05) and fivefold reduction of perioperative mortality (P < .05) among 1,566 patients undergoing carotid endarterectomy (CEA). This benefit was confirmed in a series of 3,360 CEAs performed at multiple hospitals throughout Western Canada. Statin use was independently associated with a 75% reduction (odds ratio [OR] = 0.25; 95% confidence interval [CI], 0.07-0.90) in the odds of death and 45% reduction (OR = 0.55; 95% CI, 0.32-0.95) in the odds of ischemic stroke or death among patients with symptomatic carotid disease. Further, there is some data indicating that statin use may reduce long-term incidence of restenosis following CEA. Preliminary work indicates that a similar benefit of statin use in reducing neurologic morbidity among patients undergoing carotid angioplasty and stent procedures. A number of the pleiotropic effects of statin medications may be responsible for these clinical observations. Further work is necessary to better elucidate these mechanisms, as well as to determine the optimal agents, dosing, and timing of drug administration among patients undergoing carotid interventions.     

New index for assessing the chronotropic response in patients with end-stage liver disease who are undergoing dobutamine stress echocardiography

The inability to achieve 85% of the maximum predicted heart rate (MPHR) on dobutamine stress echocardiography (DSE) is defined as chronotropic incompetence and is a predictor of major cardiac events after orthotopic liver transplantation (OLT). The majority of patients with end-stage liver disease (ESLD) receive beta-blockers for the prevention of variceal bleeding. In these patients, it is impossible to determine whether chronotropic incompetence is secondary to cirrhosis-related autonomic dysfunction or is merely a beta-blocker effect. We evaluated the usefulness of the maximum achieved heart rate (MAHR) and the heart rate reserve (HRR) in the detection of chronotropic incompetence in ESLD patients on beta-blocker therapy before DSE. We also evaluated the usefulness of a new index, the modified heart rate reserve (MHRR), in diagnosing chronotropic incompetence and predicting major cardiovascular adverse events after OLT. The study population consisted of 284 ESLD patients. The mean values of MAHR (expressed as a percentage of 85% of MPHR) and HRR were significantly lower for patients on beta-blockers versus patients off beta-blockers [97.1% versus 101.6% (t = 5.01, P < 0.001) and 71.7% versus 77.3% (t = 4.03, P < 0.001), respectively], whereas the values of MHRR were similar in patients on beta-blockers and patients off beta-blockers [102.3% versus 102.1% (t = 0.04, P = 0.97)]. A regression analysis showed a significant association of MAHR (P < 0.001) and HRR (P < 0.001) with beta-blockers, whereas MHRR was not associated with beta-blocker treatment (P = 0.92). MAHR and HRR were found to have no value for diagnosing chronotropic incompetence in ESLD patients. MHRR was not affected by beta-blocker therapy. Patients who developed heart failure (HF) and myocardial infarction (MI) after OLT had significantly lower MHRR values according to pretransplant DSE. MHRR was significantly associated with the subsequent development of HF (P = 0.01) and MI (P = 0.01) after OLT. MHRR may be useful for the determination of the target heart rate for stress testing, the diagnosis of chronotropic incompetence, and the prediction of adverse cardiac events after OLT.     

Cardiac risk stratification in patients undergoing endoluminal graft repair of abdominal aortic aneurysm: a single-institution experience with 365 patients

OBJECTIVE: Patients undergoing abdominal aortic aneurysm repair have a high incidence of coexisting cardiac disease. The traditional cardiac risk stratification for open abdominal aortic aneurysm surgery may not apply to patients undergoing endoluminal graft exclusion. The purpose of this study was to examine predictive risk factors for perioperative cardiac events. METHODS: As part of multiple prospective endograft trials approved by the US Food and Drug Administration, data for 365 patients who underwent endoluminal graft repair from 1996 to 2001 were collected. Variables included for analysis were age and sex; history of smoking; presence of hypertension, diabetes mellitus, or renal insufficiency; Eagle clinical cardiac risk factors; American Society of Anesthesiologists index; type of anesthesia administered; estimated blood loss; preoperative hemoglobin level; preoperative use of beta-blocker therapy; duration of surgery; need for iliac artery conduit; and concomitant other vascular procedures. Univariate and multivariate logistic regression analysis were used to determine which variables were predictive of an adverse perioperative cardiac event, eg, Q wave and non-Q wave myocardial infarction (MI), congestive heart failure (CHF), severe arrhythmia, and unstable angina. RESULTS: The study cohort included 322 men and 43 women (mean age, 74.2 years). Fifty-two (14.2%) postoperative cardiac events occurred: severe dysrhythmia in 15 patients (4.1%), MI in 14 patients (3.8%), non-Q wave MI in 8 patients (2.2%), CHF in 8 patients (2.2%), and unstable angina in 7 patients (1.9%). Univariate analysis demonstrated that age 70 years or older (P =.034), history of MI (P =.018), angina (P =.004), history of CHF (P <.001), two or more Eagle risk factors (P <.001), and lack of use of preoperative beta-blocker therapy (P =.005) were predictors of perioperative cardiac events. Multivariate analysis identified only age 70 years or older (P =.026), history of MI (P =.024) or CHF (P =.001), and lack of use of preoperative beta-blocker therapy (P =.007) as independent risk factors for an adverse cardiac event. CONCLUSIONS: Age 70 years or older, history of MI or CHF, and lack of use of preoperative beta-blocker therapy are independent risk factors for perioperative cardiac events in patients undergoing endoluminal graft repair.     

Risk for stroke after elective noncarotid vascular surgery

INTRODUCTION: Patients undergoing operations to treat peripheral vascular disease have systemic atherosclerosis and are at risk for stroke. However, the incidence and effect of cerebrovascular events on noncarotid vascular surgical outcomes are not well-defined. METHODS: Patients undergoing common operations for vascular disease from 1997 to 2000 were examined with data from the Veterans Affairs (VA) National Surgery Quality Improvement Project and the VA patient treatment files. Operations studied included abdominal aortic aneurysmectomy (n = 2551), aortobifemoral bypass (n = 2616), lower extremity bypass (n = 6866), and major lower extremity amputation (n = 7442). The incidence of perioperative stroke was determined, and logistic regression analysis was used to identify independent risk factors for stroke. Logistic and linear regression analyses were used to quantify the effect of postoperative stroke on adjusted mortality and length of stay. Odds ratio (OR) and 95% confidence interval (CI) were defined. P <.05 was considered significant. RESULTS: Stroke was uncommon after noncarotid vascular procedures, occurring in only 0.4% to 0.6% of patients. Independent risk factors for stroke include preoperative ventilation (OR, 11; 95% CI, 5.0-22.3; P <.001), previous stroke or transient ischemic attack (OR, 4.2; 95% CI, 2.7-6.4; P <.001), postoperative myocardial infarction (OR, 3.3; 95% CI, 1.3-8.7; P =.009), and need to return to the operating room (OR, 2.2; 95% CI, 1.4-3.5; P =.001). Factors that did not appear to be associated with stroke risk included procedure type, diabetes, renal failure, dialysis dependence, number of transfused units of blood, and hypertension. After controlling for other postoperative complications and comorbid conditions, postoperative stroke significantly increased the risk for perioperative mortality (OR, 6.3; 95% CI, 3.4-11.4; P <.001), with similar magnitude as postoperative myocardial infarction (OR, 6.3; 95% CI, 3.9-10.1; P <.001). Stroke was also associated with a 48% increase in overall length of stay. CONCLUSIONS: Stroke after noncarotid peripheral vascular surgery is uncommon, but results in markedly increased mortality and length of stay. Stroke risk is most strongly associated with previous stroke history and greater degree of illness. Patients with these associated conditions deserve particular attention to assessing and medically managing modifiable risk factors.     

Statin use associates with a lower incidence of acute kidney injury after major elective surgery

Statins abrogate ischemic renal injury in animal studies but whether they are renoprotective in humans is unknown. We conducted a population-based retrospective cohort study that included 213,347 older patients who underwent major elective surgery in the province of Ontario, Canada from 1995 to 2008. During the first 14 postoperative days, 1.9% (4020 patients), developed acute kidney injury and 0.5% (1173 patients), required acute dialysis. The 30-day mortality rate was 2.8% (5974 patients). Prior to surgery, 32% of patients were taking a statin. After statistical adjustment for patient and surgical characteristics, statin use associated with 16% lower odds of acute kidney injury (OR, 0.84; 95% CI, 0.79 to 0.90), 17% lower odds of acute dialysis (OR, 0.83; 95% CI, 0.72 to 0.95), and 21% lower odds of mortality (OR, 0.79; 95% CI, 0.74 to 0.85). Propensity score matching produced similar results. These data suggest that statins may protect against renal complications after major elective surgery and reduce perioperative mortality.     

Beta-blockers in isolated blunt head injury

BACKGROUND: The purpose of this study was to evaluate the effect of beta-blockers on patients sustaining acute traumatic brain injury. Our hypothesis was that beta-blocker exposure is associated with improved survival. STUDY DESIGN: The trauma registry and the surgical ICU databases of an academic Level I trauma center were used to identify all patients sustaining blunt head injury requiring ICU admission from July 1998 to December 2005. Patients sustaining major associated injuries (Abbreviated Injury Score > or = 4 in any body region other than the head) were excluded. Patient demographics, injury profile, Injury Severity Score, and beta-blocker exposure were abstracted. The primary outcomes measure evaluated was in-hospital mortality. RESULTS: During the 90-month study period, 1,156 patients with isolated head injury were admitted to the ICU. Of these, 203 (18%) received beta-blockers and 953 (82%) did not. Patients receiving beta-blockers were older (50 +/- 21 years versus 38 +/- 20 years, p < 0.001), had more frequent severe (Abbreviated Injury Score > or = 4) head injury (54% versus 43%, p < 0.01), Glasgow Coma Scale < or = 8 less often (37% versus 47%, p = 0.01), more skull fractures (20% versus 12%, p < 0.01), and underwent craniectomy more frequently (23% versus 4%, p < 0.001). Stepwise logistic regression identified beta-blocker use as an independent protective factor for mortality (adjusted odds ratio: 0.54; 95% CI, 0.33 to 0.91; p = 0.01). On subgroup analysis, elderly patients (55 years or older) with severe head injury (Abbreviated Injury Score > or = 4) had a mortality of 28% on beta-blockers as compared with 60% when they did not receive them (odds ratio: 0.3; 96% CI, 0.1 to 0.6; p = 0.001). CONCLUSIONS: Beta-blockade in patients with traumatic brain injury was independently associated with improved survival. Older patients with severe head injuries demonstrated the largest reduction in mortality with beta-blockade.     

Preoperative statin use and in-hospital outcomes following heart surgery in patients with unstable angina

Objective: Unstable angina (UA) is characterized by a state of coronary artery vascular inflammation and endothelial dysfunction. Statins mitigate inflammation and endothelial dysfunction and decrease mortality associated with percutaneous interventions for UA. We determined whether preoperative statin use is associated with decreased mortality and morbidity following coronary artery bypass±valve surgery for UA. Methods: Patients with CCS Class IV angina having CABG±valve surgery were identified (n=1706). A logistic regression model determined the association of preoperative statin use with in-hospital mortality (IHM). Propensity score analysis was used to match two sub-groups of patients (GrpI, on statins, n=534; GrpII, not on statins, n=534) on factors known to affect outcomes. Outcomes were IHM, intra-aortic balloon pump (IABP) use, perioperative myocardial infarction (PMI), prolonged (>24 h) ventilation (p-vent), stroke, and a composite outcome (comp) defined as any one or more of the above. Results: Of the 1706 patients, 1075 were on statins and 631 were not. Patients on statins were more likely to have isolated CABG, EF>40%, and be on a β-blocker (P=0.0001); and less likely to have renal failure, MI<7 days, CHF, and undergoing urgent/emergent surgery (P=0.0001). Unadjusted rates of IHM (9 vs. 5%, P=0.001), stroke (4.4 vs. 2.3%, P=0.015), p-vent (28.4 vs. 19%, P=0.0001), and comp (32.5 vs. 22.8%, P=0.0001) were lower in patients receiving statins. After adjustment, statin use was not associated with a reduction in IHM (OR=1.0, 95% CI=0.6–1.5, P=0.85) or comp (OR=1.1, 95% CI=0.8–1.4, P=0.69). No significant differences were found in any of the propensity-adjusted outcomes for GrpI vs. GrpII: IHM (7.1 vs. 6.4%), PMI (2.8 vs. 1.7%), IABP use (3 vs. 3.8%), stroke (3.8 vs. 3.9%), p-vent (26.4 vs. 23.8%), comp (31.5 vs. 27.5%). Conclusions: Preoperative statin use is not associated with a reduction in IHM or major morbidity following CABG±valve surgery in patients with UA.     

Atrial fibrillation after cardiac surgery: A systematic review and meta-analysis

ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established.