Comparison between serum creatinine and creatinine clearance for the prediction of postoperative mortality in patients undergoing major vascular surgery

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Secondary and Tertiary Renal Hyperparathyroidism

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate treatment of secondary (SHPT) and tertiary (THPT) renal hyperparathyroidism.

BACKGROUND

Hyperparathyroidism is common among patients with chronic kidney disease, end-stage kidney disease, and kidney transplant. The surgical management of SHPT and THPT is nuanced and requires a multidisciplinary approach. There are currently no clinical practice guidelines that address the surgical treatment of SHPT and THPT.

METHODS

Medical literature was reviewed from January 1, 1985 to present January 1, 2021 by a panel of 10 experts in SHPT and THPT. Recommendations using the best available evidence was constructed. The American College of Physicians grading system was used to determine levels of evidence. Recommendations were discussed to consensus. The American Association of Endocrine Surgeons membership reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines present the epidemiology and pathophysiology of SHPT and THPT and provide recommendations for work-up and management of SHPT and THPT for all involved clinicians. It outlines the preoperative, intraoperative, and postoperative management of SHPT and THPT, as well as related definitions, operative techniques, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Preoperative and Perioperative Care, Surgical Planning and Parathyroidectomy, Adjuncts and Approaches, Outcomes, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal management of secondary and tertiary renal hyperparathyroidism.

The comparative and added prognostic value of biomarkers to the Revised Cardiac Risk Index for preoperative prediction of major adverse cardiac events and all-cause mortality in patients who undergo noncardiac surgery

BACKGROUND

The Revised Cardiac Risk Index (RCRI) is a widely acknowledged prognostic model to estimate preoperatively the probability of developing in-hospital major adverse cardiac events (MACE) in patients undergoing noncardiac surgery. However, the RCRI does not always make accurate predictions, so various studies have investigated whether biomarkers added to or compared with the RCRI could improve this.

OBJECTIVES

Primary: To investigate the added predictive value of biomarkers to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Secondary: To investigate the prognostic value of biomarkers compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Tertiary: To investigate the prognostic value of other prediction models compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery.

SEARCH METHODS

We searched MEDLINE and Embase from 1 January 1999 (the year that the RCRI was published) until 25 June 2020. We also searched ISI Web of Science and SCOPUS for articles referring to the original RCRI development study in that period.

SELECTION CRITERIA

We included studies among adults who underwent noncardiac surgery, reporting on (external) validation of the RCRI and: - the addition of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of the RCRI to other models. Besides MACE, all other adverse outcomes were considered for inclusion.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form based on the CHARMS checklist. Independent pairs of authors screened references, extracted data and assessed risk of bias and concerns regarding applicability according to PROBAST. For biomarkers and prediction models that were added or compared to the RCRI in ≥ 3 different articles, we described study characteristics and findings in further detail. We did not apply GRADE as no guidance is available for prognostic model reviews.

MAIN RESULTS

We screened 3960 records and included 107 articles.   Over all objectives we rated risk of bias as high in ≥ 1 domain in 90% of included studies, particularly in the analysis domain. Statistical pooling or meta-analysis of reported results was impossible due to heterogeneity in various aspects: outcomes used, scale by which the biomarker was added/compared to the RCRI, prediction horizons and studied populations.  Added predictive value of biomarkers to the RCRI Fifty-one studies reported on the added value of biomarkers to the RCRI. Sixty-nine different predictors were identified derived from blood (29%), imaging (33%) or other sources (38%). Addition of NT-proBNP, troponin or their combination improved the RCRI for predicting MACE (median delta c-statistics: 0.08, 0.14 and 0.12 for NT-proBNP, troponin and their combination, respectively). The median total net reclassification index (NRI) was 0.16 and 0.74 after addition of troponin and NT-proBNP to the RCRI, respectively. Calibration was not reported. To predict myocardial infarction, the median delta c-statistic when NT-proBNP was added to the RCRI was 0.09, and 0.06 for prediction of all-cause mortality and MACE combined. For BNP and copeptin, data were not sufficient to provide results on their added predictive performance, for any of the outcomes. Comparison of the predictive value of biomarkers to the RCRI  Fifty-one studies assessed the predictive performance of biomarkers alone compared to the RCRI. We identified 60 unique predictors derived from blood (38%), imaging (30%) or other sources, such as the American Society of Anesthesiologists (ASA) classification (32%). Predictions were similar between the ASA classification and the RCRI for all studied outcomes. In studies different from those identified in objective 1, the median delta c-statistic was 0.15 and 0.12 in favour of  BNP and NT-proBNP alone, respectively, when compared to the RCRI, for the prediction of MACE. For C-reactive protein, the predictive performance was similar to the RCRI. For other biomarkers and outcomes, data were insufficient to provide summary results. One study reported on calibration and none on reclassification. Comparison of the predictive value of other prognostic models to the RCRI   Fifty-two articles compared the predictive ability of the RCRI to other prognostic models. Of these, 42% developed a new prediction model, 22% updated the RCRI, or another prediction model, and 37% validated an existing prediction model. None of the other prediction models showed better performance in predicting MACE than the RCRI. To predict myocardial infarction and cardiac arrest, ACS-NSQIP-MICA had a higher median delta c-statistic of 0.11 compared to the RCRI. To predict all-cause mortality, the median delta c-statistic was 0.15 higher in favour of ACS-NSQIP-SRS compared to the RCRI. Predictive performance was not better for CHADS₂, CHA₂DS₂-VASc, R₂CHADS₂, Goldman index, Detsky index or VSG-CRI compared to the RCRI for any of the outcomes. Calibration and reclassification were reported in only one and three studies, respectively.

AUTHORS' CONCLUSIONS

Studies included in this review suggest that the predictive performance of the RCRI in predicting MACE is improved when NT-proBNP, troponin or their combination are added. Other studies indicate that BNP and NT-proBNP, when used in isolation, may even have a higher discriminative performance than the RCRI. There was insufficient evidence of a difference between the predictive accuracy of the RCRI and other prediction models in predicting MACE. However, ACS-NSQIP-MICA and ACS-NSQIP-SRS outperformed the RCRI in predicting myocardial infarction and cardiac arrest combined, and all-cause mortality, respectively. Nevertheless, the results cannot be interpreted as conclusive due to high risks of bias in a majority of papers, and pooling was impossible due to heterogeneity in outcomes, prediction horizons, biomarkers and studied populations. Future research on the added prognostic value of biomarkers to existing prediction models should focus on biomarkers with good predictive accuracy in other settings (e.g. diagnosis of myocardial infarction) and identification of biomarkers from omics data. They should be compared to novel biomarkers with so far insufficient evidence compared to established ones, including NT-proBNP or troponins. Adherence to recent guidance for prediction model studies (e.g. TRIPOD; PROBAST) and use of standardised outcome definitions in primary studies is highly recommended to facilitate systematic review and meta-analyses in the future.

The association of estimated glomerular filtration rate with outcomes following infrainguinal bypass for peripheral arterial disease

OBJECTIVE

Chronic kidney disease (CKD) is a recognized predictor of long-term survival, frequently coexisting with peripheral arterial disease (PAD). Estimated glomerular filtration rate (eGFR) is a more accurate marker of renal function than creatinine. This study sought to determine the graded impact of CKD, defined by eGFR, on infrainguinal lower extremity bypass (LEB) outcomes.

METHODS

This retrospective study examined 44,332 patients from the Vascular Quality Initiative database who underwent LEB between January 2003 and November 2019. The GFR was estimated using the Modification of Diet in Renal Disease equation. Multivariable logistic regression was used to study perioperative mortality and Kaplan-Meier survival estimation and multivariable Cox regression were used to evaluate 5-year mortality, 1-year major amputation, and major amputation/death.

RESULTS

The 30-day mortality odds was increased for CKD 3 (odds ratio [OR], 1.58; 95% confidence interval [CI], 1.32-1.91; P < .001) and CKD 5 (OR, 3.08; 95% CI, 2.45-3.87; P < .001) relative to CKD 1 to 2. Comparing CKD stages 3, 4, and 5 with CKD 1 and 2, there was a stepwise increase in the adjusted hazard of 5-year mortality (hazard ratio [HR], 1.18; 95% CI, 1.09-1.27; P < .001), (HR, 1.73; 95% CI; 1.47-2.03; P < .001) and (HR, 2.58; 95% CI, 2.33-3.84; P < .001), respectively. Although the risk of 1-year death or major amputation did not differ for CKD 3 compared with CKD 1, this was 50% higher for CKD 4 (HR, 1.50; 95% CI, 1.26-1.78; P < .001) and doubled for CKD 5 (HR, 2.07; 95% CI, 1.87-2.29; P < .001) compared with CKD 1 and 2. The adjusted HR for major amputation in 1 year was 0.81 (95% CI, 0.71-0.92; P = .002), 1.14 (95% CI, 0.84-1.54; P = .396) and 1.56 (95% CI,1.31-1.84; P < .001) for CKD 3, 4, and 5, respectively, compared with CKD 1 and 2.

CONCLUSIONS

The estimated GFR is a useful predictor of postoperative mortality, overall survival, and/or amputation after LEB in patients with PAD. It should be considered in the preoperative risk-benefit analysis process to guide patient selection in the population with concomitant PAD and CKD being considered for LEB.

Chronic Kidney Disease Class Predicts Mortality After Abdominal Aortic Aneurysm Repair in Propensity-matched Cohorts From the Medicare Population

INTRODUCTION

Chronic kidney disease (CKD) predicts mortality after abdominal aortic aneurysm (AAA) repair. Few studies are adequately powered to stratify outcomes by CKD severity. This study assesses the effect of CKD severity on survival after AAA repair.

METHODS

Patients who underwent AAA repair from 2006 to 2007 were retrospectively identified in the Medicare database and stratified by CKD class as follows: normal (CKD class 1 and 2), moderate (CKD class 3), and severe (CKD class 4 and 5). Propensity matching (30:1) by clinical factors and procedure type was performed to derive well-matched comparative cohorts. Primary outcomes were 30-day and long-term mortality; secondary outcomes included hospital length of stay and cost.

RESULTS

A total of 47,715 patients were included (96.7% normal, 1.88% moderate, and 1.65% severe). Propensity matching was corrected for differences between cohorts. Thirty-day mortality was higher in moderate (5.7% vs normal 2.5%; P < 0.01) and severe (9.9% vs normal 1.8%; P < 0.01) groups. Hospital length of stay increased with CKD severity (4.4 ± 3.7 days normal vs 6.5 ± 4.2 days moderate CKD; P < 0.01/4.7 ± 3.8 days normal vs 9.1 ± 4.5 days severe CKD; P < 0.01) as did cost ($23 ± 14K normal vs $25 ± 16K moderate; P < 0.01 /$22 ± 11K normal vs $29 ± 22K severe; P < 0.01). Three-year survival favored the normal cohort (80% vs 64% moderate; log rank P < 0.01 /82% normal vs 44% severe; log rank P < 0.01).

CONCLUSIONS

CKD severity is an important predictor of perioperative mortality and long-term survival after AAA repair in propensity-matched cohorts. The 5-fold increase in 30-day mortality and 44% in 3-year survival suggest that elective AAA repair is contraindicated in most severe CKD patients.

Preoperative Laboratory Testing

Routine preoperative testing is not cost-effective, because it is unlikely to identify significant abnormalities. Abnormal findings from routine testing are more likely to be false positive, are costly to pursue, introduce a new risk, increase the patient's anxiety, and are inconvenient to the patient. Abnormal findings rarely alter the surgical or anesthetic plan, and there is usually no association between perioperative complications and abnormal laboratory results. Incidental findings and false positive results may lead to increased hospital visits and admissions. Preoperative testing needs to be done based on a targeted history and physical examination and the type of surgery.

Preoperative estimates of glomerular filtration rate as predictors of outcome after surgery: a systematic review and meta-analysis

BACKGROUND

Kidney dysfunction is a strong determinant of prognosis in many settings.

METHODS

A systematic review and meta-analysis was undertaken to explore the relationship between estimated glomerular filtration rate (eGFR) and adverse outcomes after surgery. Cohort studies reporting the relationship between eGFR and major outcomes, including all-cause mortality, major adverse cardiovascular events, and acute kidney injury after cardiac or noncardiac surgery, were included.

RESULTS

Forty-six studies were included, of which 44 focused exclusively on cardiac and vascular surgery. Within 30 days of surgery, eGFR less than 60 m l · min · 1.73 m(-2) was associated with a threefold increased risk of death (multivariable adjusted relative risk [RR] 2.98; 95% confidence interval [CI] 1.95-4.96) and acute kidney injury (adjusted RR 3.13; 95% CI 2.22-4.41). An eGFR less than 60 ml · min · 1.73(-2) m was associated with an increased risk of all-cause mortality (adjusted RR 1.61; 95% CI 1.38-1.87) and major adverse cardiovascular events (adjusted RR 1.49; 95% CI 1.32-1.67) during long-term follow-up. There was a nonlinear association between eGFR and the risk of early mortality such that, compared with patients having an eGFR more than 90 ml · min · 1.73m(-2) the pooled RR for death at 30 days in those with an eGFR between 30 and 60 ml · min · 1.73 m(-2) was 1.62 (95% CI 1.43-1.80), rising to 2.85 (95% CI 2.49-3.27) in patients with an eGFR less than 30 ml · min · 1.73 m(-2) and 3.75 (95% CI 3.44-4.08) in those with an eGFR less than 15 ml · min · 1.73 m(-2).

CONCLUSION

: There is a powerful relationship between eGFR, and both short- and long-term prognosis after, predominantly cardiac and vascular, surgery.

Effectiveness of non-cardiac preoperative testing in non-cardiac elective surgery: a systematic review

Elective surgery is usually preceded by preoperative diagnostics to minimize risk. The results are assumed to elicit preventive measures or even cancellation of surgery. Moreover, physicians perform preoperative tests as a baseline to detect subsequent changes. This systematic review aims to explore whether preoperative testing leads to changes in management or reduces perioperative mortality or morbidity in unselected patients undergoing elective, non-cardiac surgery. We systematically searched all relevant databases from January 2001 to February 2011 for studies investigating the relationship between preoperative diagnostics and perioperative outcome. Our methodology was based on the manual of the Ludwig Boltzmann Institute for Health Technology Assessment, the Scottish Intercollegiate Guidelines Network (SIGN) handbook, and the PRISMA statement for reporting systematic reviews. One hundred and one of the 25 281 publications retrieved met our inclusion criteria. Three test grid studies used a randomized controlled design and 98 studies used an observational design. The test grid studies show that in cataract surgery and ambulatory surgery, there are no significant differences between patients with indicated preoperative testing and no testing regarding perioperative outcome. The observational studies do not provide valid evidence that preoperative testing is beneficial in healthy adults undergoing non-cardiac surgery. There is no evidence derived from high-quality studies that supports routine preoperative testing in healthy adults undergoing non-cardiac surgery. Testing according to pathological findings in a patient's medical history or physical examination seems justified, although the evidence is scarce. High-quality studies, especially large randomized controlled trials, are needed to explore the effectiveness of indicated preoperative testing.

Preoperative cardiac assessment in patients undergoing major vascular surgery

The aim of this study was to evaluate the effectiveness of a preoperative standardized cardiac assessment in patients undergoing major vascular surgery. From January 2005 to December 2006, 1446 elective interventions for major vascular diseases (carotid stenosis, CS; abdominal aortic aneurysm, AAA; peripheral arterial obstructive disease, PAOD) were performed; 1090 out of these patients underwent preoperative diagnostic assessment on an outpatient basis. Thirty-day results in terms of cardiac mortality and morbidity rates were recorded. Patients suffered from a CS in 578 cases (53%), an AAA in 303 cases (27.8%) and a PAOD in 209 cases (19.2%). Four hundred thirty-two patients (39.6%) underwent further evaluation of cardiac functional capacity with non-invasive stress testing. Sixteen patients were successfully treated prior to vascular surgery. Thirty-day cardiac mortality and morbidity rates were 0.2% and 3.9%, respectively. A positive preoperative non-invasive stress testing did not affect 30-day cardiac outcomes. In conclusion, the use of an accurate preoperative cardiac assessment allowed us to obtain satisfactory perioperative results in patients undergoing major vascular surgery. Routine preoperative evaluation with non-invasive stress testing did not seem to improve perioperative cardiac results.

Surgery in the patient with renal dysfunction

Preoperative evaluation of patients with renal dysfunction often requires the collaborative efforts of the primary care physician, nephrologist, surgeon, and anesthesiologist. Renal dysfunction is typically a spectrum of disease with multisystem effects. Optimization of preexisting medical issues is the key, as is a thorough understanding of the potential perioperative risks for further renal injury. Surgical or anesthetic techniques may require alteration for the patient with significant renal dysfunction. Identification of those at risk for renal injury may allow for preventative therapies in the perioperative period. This article focuses on defining the population at risk, a framework for preoperative evaluation, and developments in the area of perioperative renal protection.

Surgery in the patient with renal dysfunction

Preoperative evaluation of patients with renal dysfunction often requires the collaborative efforts of the primary care physician, nephrologist, surgeon, and anesthesiologist. Renal dysfunction is typically a spectrum of disease with multisystem effects. Optimization of preexisting medical issues is the key as is a thorough understanding of the potential perioperative risks for further renal injury. Surgical or anesthetic techniques may require alteration for the patient with significant renal dysfunction. Identification of those at risk for renal injury may allow for preventative therapies in the perioperative period. This article focuses on defining the population at risk, a framework for preoperative evaluation, and developments in the area of perioperative renal protection.

[Coronary risk assessment in the management of patients undergoing noncardiac vascular surgery]

Patients scheduled for noncardiac vascular surgery are at significant risk of cardiovascular morbidity and mortality due to underlying symptomatic or asymptomatic coronary artery disease. This review will give an overview of current preoperative cardiac risk assessment strategies for patients undergoing noncardiac vascular surgery. Clinical cardiac risk scores are useful tools for the simple identification of patients with an increased perioperative cardiac risk. These risk scores include factors as age, history of myocardial infarction, angina pectoris, congestive heart failure, cerebrovascular events, diabetes mellitus, and renal dysfunction. Based on these cardiac risk scores further cardiac testing might be warranted in patients at increased risk. Recent developments in laboratory tests, noninvasive cardiac imaging, cardiac stress testing, and invasive cardiac imaging in the preoperative work-up of vascular surgical patients are reviewed.

Perioperative medical management of ischemic heart disease in patients undergoing noncardiac surgery

PURPOSE OF REVIEW

Cardiovascular disease is the leading cause of death after anesthesia and surgery. The preoperative identification of patients with underlying coronary artery disease is important to initiate appropriate treatment strategies in order to reduce the risk of perioperative complications. The current review will discuss new insights in the field of perioperative medicine that can be applied to clinical practice or stimulate further investigation.

RECENT FINDINGS

Recent findings in the past year have developed preoperative risk stratification in terms of simplicity, safety, accuracy and cost-effectiveness. Natriuretic peptides have been demonstrated to be promising new preoperative risk markers. Although recommended in high-risk patients, noninvasive cardiac stress testing may be safely omitted in patients at intermediate risk. The antiischemic properties of beta-blockers have been well described. In clinical practice, however, adequate beta-blocker dosage, tight perioperative heart rate control and continuation of beta-blockers after surgery may also be important factors. Statins have emerged as promising drugs with perioperative cardioprotective properties. Before recommending routine administration of statin therapy, however, more clinical trials are needed.

SUMMARY

New perceptions in perioperative medical management and novel developments in surgical and anesthesiology techniques continue to improve the cardiovascular outcome of patents undergoing major noncardiac surgery.

Mortalité hospitalière et durée de séjour des patients non programmés en médecine interne: valeur pronostique de paramètres biochimiques usuels à l'admission

PURPOSE

Little is known about prognosis values of biochemical markers in internal medicine patients. We have examined retrospectively the relationship between inhospital mortality or stay duration and several biochemical markers commonly performed on admission in internal medicine patients.

METHODS

Among all stays unplanned in our department during the year 2004, we collected data about 8 blood biochemical markers (sodium, potassium, chloride, bicarbonate, anion gap, urea nitrogen, creatinin, proteins), performed between the day before and the day after admission. Mixed Cox regression models computed hazard ratios for mortality associated with biochemical markers concentration. The relationship between biochemical markers concentration and duration stay was investigated in mixed linear regression models.

RESULTS

In 2004 our department totalized 1199 unplanned stays by 1054 distinct patients (age: 69.9+/-19.2 y, women: 59.2%), among which 59 deceased during stay. Biochemical markers were available for 977 (81.5%) stays (stay duration: 17.5+/-16.0 days). Inhospital mortality was significantly associated with plasma concentration on admission of potassium, proteins, anion gap and with urea nitrogen/creatinin ratio. Among survivors, duration stay was significantly associated with plasma concentration on admission of sodium, chlore, and anion gap.

CONCLUSION

Biochemical markers performed on admission need particular attention as they provide immediate information about short term prognosis of internal medicine patients.

Creatinine clearance but not serum creatinine alone predicts long-term postoperative survival after lower extremity revascularization

BACKGROUND

Renal insufficiency is a well-described risk factor for perioperative morbidity and shortened survival after major vascular procedures. Due to the potential inaccuracy of serum creatinine levels alone in measuring kidney function, our aim was to determine whether estimated creatinine clearance more consistently predicted long-term survival.

METHODS

A retrospective review of one institution's vascular registry was performed. Logistic regression analysis was conducted to determine independent predictors of 1-, 2- and 3-year postoperative mortality. Creatinine clearance was estimated as [140 - age (years)] x weight (kg)/72 x serum creatinine (mg/dl), multiplied by 0.85 for women.

RESULTS

A total of 252 consecutive patients underwent infrainguinal bypass procedures between August 1999 and May 2000. Demographics included average age 68 years, 65% male, 74% diabetic, 12% dialysis-dependent, 23% history of congestive heart failure, 12% history of stroke and 20% serum creatinine >2 mg/dl. One-year mortality was 16% (n = 40), 2-year mortality was 25% (n = 64), and 3-year mortality was 35% (n = 88). There was no difference in serum creatinine values between survivors and non-survivors at 1 year (1.8 vs. 1.9, p = 0.80), 2 years (1.8 vs. 2.0, p = 0.62) or 3 years (1.8 vs. 2.0, p = 0.24), and creatinine >2 mg/dl did not predict long-term adverse outcomes. In contrast, reduced creatinine clearance (< or =60 ml/min) was an independent predictor of mortality regardless of dialysis status (1 year: OR = 2.53, p = 0.014; 2 years: OR = 2.46, p = 0.004; 3 years: OR = 2.45, p = 0.001), and creatinine clearance was higher for survivors versus non-survivors at all 3 time points (1 year: 70.2 vs. 49.5, p = 0.003; 2 years: 72.3 vs. 51.2, p < 0.0001; 3 years: 74.7 vs. 52.6, p < 0.0001). Other independent predictors of mortality included a history of stroke (1 year: OR = 3.28, p = 0.008; 2 years: OR = 2.55, p = 0.025; 3 years: OR = 2.35, p = 0.038) and congestive heart failure (1 year: OR = 2.86, p = 0.006; 2 years: OR = 2.54, p = 0.005; 3 years: OR = 2.13, p = 0.017).

CONCLUSIONS

Independent of dialysis status, a decreased creatinine clearance, but not elevated serum creatinine alone, is an independent predictor of mortality after lower extremity arterial reconstruction. Determination of creatinine clearance should replace serum creatinine in the preoperative risk evaluations of patients undergoing major vascular surgical procedures.

Identification of risk factors for perioperative mortality in acute mesenteric ischemia

INTRODUCTION

Acute intestinal ischemia is in most cases a lethal condition with a low survival rate. Risk factors of perioperative mortality are poorly defined. The aim of this study was to define risk factors that predict an adverse outcome of acute mesenteric ischemia (AMI).

METHODS

A total of 132 consecutive patients (73 men, 59 women), mean+/-SD age 71.96+/-13.64 years, who underwent surgery because of AMI in a university tertiary care center were evaluated over a period of 10 years. Clinical features, laboratory findings, etiologic factors, and surgical procedures were recorded and assessed as possible risk factors for perioperative mortality.

RESULTS

Of 132 patients, 86 (65.2%) died during the perioperative period as a direct result of AMI. Significant univariate predictors of perioperative mortality were age (P=0.01), cardiopathy (P=0.002), digoxin intake (P=0.015), shock (P=0.01), urea plasma level (P<0.001), creatinine (P<0.001), potassium (P=0.042), low pH (P=0.015) and bicarbonate (P=0.035); hemoglobin>or=2.48 mmol/L (P=0.035); time delay to surgery (P=0.023); colonic involvement (P<0.001); small and large bowel involvement (P<0.001); arterial versus venous ischemia (P=0.007); and intestinal resection (P<0.001). In the multivariate analysis, the variables previous cardiac illness (P=0.045), urea plasma levels (P<0.001), and small and large bowel involvement were identified as independent risk factors of perioperative mortality. Intestinal resection (P<0.001) was a favorable predictor.

CONCLUSIONS

Age, time delay to surgery, shock, and acidosis significantly increase the risk of mortality due to AMI, whereas intestinal resection has a protective effect. However, only previous cardiac illness, acute renal failure, and large bowel ischemia have a negative effect as independent risk factors of mortality of AMI.

Can Statins Reduce Perioperative Morbidity and Mortality in Patients Undergoing Non-Cardiac Vascular Surgery?

AIMS

To determine whether statins can reduce perioperative morbidity and mortality in patients undergoing non-cardiac vascular surgery.

METHODS

A search using Pubmed was performed to identify reports in English. The search terms were: "statins", "perioperative morbidity", "perioperative mortality" and "vascular surgery". We excluded studies dealing with the effect of statins in cardiac surgery. Retrieved articles were manually searched.

RESULTS

Current evidence shows that statins decrease perioperative morbidity and mortality in patients undergoing non-cardiac vascular surgery. Any benefit probably occurs soon (within a month) after initiating treatment.

CONCLUSIONS

Appropriately designed trials need to confirm the beneficial effect of perioperative statin therapy in various patient categories. The optimal duration and dose of perioperative statin therapy should be defined.

Peri-operative Renal Function and Outcome after Orthotopic Heart Transplantation

BACKGROUND

Renal insufficiency is an established risk factor in patients undergoing cardiovascular surgery. We sought to evaluate the relationship between renal function and outcomes after orthotopic heart transplantation (OHT).

METHODS

We conducted a retrospective review of 622 adults who underwent 628 consecutive OHTs between 1994 and 2001 at our institution. The recipients were divided into either normal (Group 1) or impaired (Group 2) pre-operative renal function. Impaired renal function was defined as creatinine clearance (CrCl) < 40 ml/min (Cockroft-Gault formula). Meanwhile, patients in Group 1 (normal) were defined by CrCl > or = 40 ml/min. The primary end points of the study were early and late mortality. The secondary end point included post-operative renal failure defined by the requirement of dialysis or renal allograft in the early post-operative period. The Kaplan-Meier method was used to determine actuarial survival.

RESULTS

Early mortality was 7% (38/531) in Group 1 and 17% (16/96) in Group 2 (p = 0.002). Similarly, the death rate per 100 patient-years was 4.8 and 8.1 for the groups, respectively (p = 0.03). Nine percent of patients in Group 1 required post-operative dialysis (49/531), whereas 32% of recipients in Group 2 required this intervention (31/96) (p < 0.001). Early mortality was 41% for patients requiring post-operative dialysis and 3% for those not requiring such intervention (p < 0.001). Early mortality after post-operative dialysis was 41% (20/49) in Group 1 and 42% (13/31) in Group 2 (p = 0.2).

CONCLUSIONS

CrCl < 40 ml/min is a useful marker for increased post-operative renal failure and mortality. Recipients who require post-operative dialysis have greatly increased mortality regardless of pre-operative CrCl. Dialysis in patients after heart transplantation carries a prohibitive risk. Dialysis as a bridge to renal transplantation may reduce this high mortality rate.