Elsayed Elmistekawy

Clinical Impact of Mild Acute Kidney Injury After Cardiac Surgery

BACKGROUND Dialysis-dependent renal failure occurs infrequently after cardiac surgery but leads to substantial morbidity and mortality. In contrast, milder degrees of acute kidney injury (AKI), based on small increases in serum creatinine, occur frequently but the independent impact of mild AKI on outcome remains unclear. METHODS Between January 2010 and December 2012, 3,869 consecutive patients undergoing cardiac surgery comprised the study cohort. Acute kidney injury was defined according to the AKI Network criteria as stage I, II, or III. A nonparsimonious multivariable logistic regression model including preoperative and intraoperative variables was constructed to determine a propensity score for the development of stage I AKI followed by a greedy matching algorithm to create 1:1 propensity-matched pairs. RESULTS The incidence of stage I AKI in the entire cohort was 22.4%. Stage I AKI patients were more likely to be older; to have diabetes mellitus, hypertension, preoperative renal dysfunction, and poorer left ventricle function; and to require more urgent surgery and longer cardiopulmonary bypass. After propensity matching, the 833 matched pairs were similar in terms of all of the above characteristics (all p > 0.5). Within the matched cohort, AKI patients had higher mortality (2.6% versus 1.2%, p = 0.01), higher incidence of neurologic dysfunction (15.2% versus 8.1%, p < 0.001), and longer duration of mechanical ventilation (41.7 ± 125.0 versus 19.3 ± 58.6 hours, p < 0.001). Intensive care unit stay (5.2 ± 10.7 versus 2.7 ± 3.8 days, p < 0.0001), and hospital length of stay (17.9 ± 20.1 versus 14.7 ± 18.3 days, p = 0.0007) was significantly longer for matched AKI patients. CONCLUSIONS Patients with even mild degrees of AKI have increased mortality and morbidity compared with their matched counterparts. Interventions that prevent or mitigate AKI after cardiac surgery can yield substantial clinical benefit.

Preoperative anaemia is a risk factor for mortality and morbidity following aortic valve surgery.

OBJECTIVES The impact of anaemia on patients undergoing aortic valve surgery has not been well studied. We sought to evaluate the effect of anaemia on early outcomes following aortic valve replacement (AVR). METHODS All patients undergoing non-emergent aortic valve surgery (n = 2698) with or without other concomitant procedures between 1997 and 2010 were included. Preoperative anaemia was defined as per World Health Organization guidelines as haemoglobin (Hb) < 130 g/l in men and Hb < 120 g/l in women. Multivariable analyses were used to determine the association between preoperative anaemia and postoperative outcomes. RESULTS The prevalence of preoperative anaemia was 32.2%. Patients with anaemia were older (71 ± 12 vs 66 ± 13 years, P < 0.001), more likely to have urgent surgery, recent MI, higher creatinine level and impaired preoperative left ventricular function. Overall unadjusted mortality was 2.8% in non-anaemic patients vs 8% in anaemic patients. Anaemic patients were more likely to require renal replacement therapy (11 vs 3%, P < 0.0001) and prolonged ventilation (24 vs 10%, P < 0.0001). Following multivariable adjustment, lower preoperative Hb was an independent predictor of mortality (odds ratio 1.19, 95% CI: 1.04-1.34, P = 0.007) and composite morbidity (odds ratio 1.36, 95% CI: 1.05-1.77, P = 0.02) after AVR. Mortality and composite morbidity were significantly higher with lower levels of preoperative Hb. CONCLUSIONS Preoperative anaemia is a common finding in patients undergoing aortic valve surgery and is an important and potentially modifiable risk factor for postoperative morbidity and mortality.

Is Bilateral Internal Thoracic Artery Use Safe in the Elderly

Abstract  Background: The strategy of bilateral mammary artery grafting is often not considered for elderly patients due to perceived concerns of increased morbidity and mortality. The objective of this study is to explore the safety of bilateral mammary in elderly patients.Methods: Out of 7746 patients who underwent coronary artery bypass grafting using at least one internal thoracic artery (ITA), there were 3940 patients aged 65 years or greater, and of those, 3581 patients had a single ITA (SITA) and 359 patients had bilateral ITAs (BITAs). The primary outcome was the incidence of major adverse cardiac or cerebrovascular events (MACCEs). Secondary outcomes included re‐exploration for bleeding, blood transfusions, sternal wound infections, and intensive care unit and hospital length of stay. Results: The incidence of mortality and MACCE were similar in both groups (mortality BITA 2.6%, SITA 3.6%, p = 0.25, MACCE BITA 8.5%, SITA 6.1%, p = 0.13). Superficial and deep sternal site infections were significantly more prevalent in the BITA group than the SITA group [superficial OR 0.42, 95% CI [0.23 – 0.75] (p = 0.003) and deep OR 0.29, 95% CI [0.14 – 0.58 (p = 0.0005)]. Conclusion: Use of BITA is safe in the elderly with respect to mortality and early cardiovascular outcome. BITA use in the elderly is associated with an increased risk of sternal wound infection. Our experience in this situation suggests that there is a maximum age (approximately 74 years) beyond which the combined risk of MACCE and wound complications supersedes the benefits in terms of sternal infections. (J Card Surg 2012;27:1‐5)

Off-pump coronary artery bypass grafting does not preserve renal function better than on-pump coronary artery bypass grafting: results of a case-matched study.

OBJECTIVE Controversy exists regarding the perioperative renal effects of off-pump versus on-pump coronary artery bypass grafting. Large case-matched and randomized comparisons have shown conflicting results. This study focuses on this clinical controversy. METHODS We studied 5589 consecutive patients from a single center who underwent off-pump or on-pump coronary artery bypass grafting between 2002 and 2010. All preoperative, intraoperative, and postoperative data were prospectively collected. Patients were matched by using a nearest neighbor matching estimation method for average treatment effects, with bias correction (Stata 11.2, StataCorp, College Station, Tex). The matching characteristics were age, gender, body mass index, hypertension, diabetes, peripheral vascular disease, cerebrovascular disease, left ventricular grade, preoperative serum creatinine, operative priority, and Cardiac Anesthesia Risk Evaluation score. RESULTS The mean patient age was 64.9 ± 10.0 years, and 4387 (78.5%) were male. Mean calculated preoperative creatinine clearance was 82.0 ± 32.6 mL/min. Perioperative mortality was 1.5% with off-pump coronary artery bypass grafting and 1.7% with on-pump coronary artery bypass grafting (P = .6). The mean change in creatinine clearance, from the preoperative value to the lowest postoperative value, was -6.3 ± 14.1 mL/min with off-pump coronary artery bypass grafting versus -5.0 ± 15.5 mL/min with on-pump coronary artery bypass grafting (P = .06). After matching, patients undergoing off-pump coronary artery bypass grafting had a greater creatinine increase and greater loss of creatinine clearance postoperatively compared with patients undergoing on-pump coronary artery bypass grafting (both P < .05). Requirements for de novo postoperative dialysis were equivalent at 2.6% in off-pump coronary artery bypass grafting versus 2.1% in on-pump coronary artery bypass grafting (P = .4). Median postoperative hospital stay was 8 days in both groups (P = .8). CONCLUSIONS Off-pump coronary artery bypass grafting does not preserve renal function to a greater extent than on-pump coronary artery bypass grafting. In fact, a trend to the reverse exists with no clinically harmful effects.

Determinants of Left Ventricular Dysfunction After Repair of Chronic Asymptomatic Mitral Regurgitation

BACKGROUND The evidence supporting early surgical intervention in patients with chronic asymptomatic mitral regurgitation (MR) is steadily accumulating. Although left ventricular (LV) enlargement and preoperative pulmonary hypertension are considered when deciding on surgical intervention, the threshold above which these factors influence clinical outcomes remains poorly defined. METHODS One-hundred fifty asymptomatic patients of aged 59.3 ± 13.4 years underwent mitral valve repair of severe MR caused by myxomatous degeneration between 2001 and 2012. Mean preoperative left atrial diameter, LV end-systolic diameter (LVESD), and right ventricular systolic pressure were 41.2 ± 6.9 mm, 34.6 ± 5.4 mm, and 38.4 ± 11.8 mm Hg, respectively. Preoperative LV ejection fraction (LVEF) was greater than 60% in 136 (91%) patients, and none had preoperative atrial fibrillation. Clinical and echocardiographic follow-up averaged 3.3 years and extended to 9.1 years. RESULTS There were no perioperative deaths. Five-year survival and freedom from recurrent MR greater than or equal to 2+ were 93.4% ± 3.2% and 94.0% ± 3.2%, respectively. A threshold LVESD indexed to body surface area greater than 19 mm/m(2) (hazard ratio [HR], 3.5 ± 2.0; p = 0.03) and a preoperative right ventricular systolic pressure greater than 45 mm Hg (HR, 3.8 ± 12.1; p = 0.01) were independently associated with postoperative LV dysfunction, defined as a LVEF less than 60%. CONCLUSIONS Mitral valve repair can be performed with favorable early and late outcomes in patients with asymptomatic severe MR. The presence of minimal LV enlargement and preoperative pulmonary hypertension were associated with postoperative LV dysfunction in this otherwise healthy population. Mitral valve repair may be considered in asymptomatic patients with an indexed LVESD (ILVESD) greater than 19 mm/m(2) or preoperative right ventricular systolic pressure greater than 45 mm Hg.

Perioperative Deaths After Mitral Valve Operations May Be Overestimated by Contemporary Risk Models

BACKGROUND Percutaneous therapies to manage mitral regurgitation are emerging as an alternative to conventional operations, especially for patients with a high estimated perioperative risk. However, contemporary risk models may not accurately reflect outcomes at reference mitral valve centers. The purpose of this study was to describe perioperative mortality rates after mitral valve operations in a contemporary cohort. METHODS Between 2001 and 2011, 1,154 patients underwent mitral valve operations at a reference center. Of these, 851 underwent repair and 303 underwent replacement. Concomitant coronary artery bypass grafting was performed in 201 (17%). The Society of Thoracic Surgeons (STS) risk score version 2.73 and European System for Cardiac Operative Risk Evaluation (EuroSCORE) II were used to estimate the number of perioperative deaths. RESULTS The observed perioperative mortality was 1.0%. The STS score was 2.3%±2.6% and was higher than the observed mortality rate for each of the STS subgroups (all p<0.001). The EuroSCORE II expected mortality was 3.0%±3.4% and was greater than the observed mortality rate for isolated and combined procedures (both p<0.001). The STS and EuroSCORE II provided fair death discrimination, with an area under the receiver operating characteristic curve of 0.74 and 0.67, respectively. CONCLUSIONS Although current risk models aid in risk stratifying patients, the contemporary perioperative mortality rate at a reference mitral valve center is significantly lower than expected. The use of alternate therapies must therefore take into consideration differences in perioperative risk based on the treating center.

Recurrent Cardiac Constriction After Complete Pericardiectomy

We present a patient with recurrent constrictive physiology resulting from exuberant post-operative fibrosis after complete pericardiectomy. The patient underwent a repeat stripping procedure. At surgery, there was an extensive fibrotic and calcified rind around the heart. The recurrence of constriction physiology after complete pericardiectomy in non-tuberculous pericarditis is a rarely reported in literature. The management supports repeat surgery and the potential value of steroid administration.

Apico-Aortic Conduit for severe aortic stenosis: Technique, applications, and systematic review.

Patients referred for aortic valve replacement are often elderly and may have increased surgical risk associated with ascending aortic calcification, left ventricular dysfunction, presence of coronary artery disease, previous surgery, and/or presence of several co-morbidities. Some of these patients may not be considered candidates for conventional surgery because of their high risk profile. While transcatheter aortic valve replacement constitutes a widely accepted alternative, some patients may not be eligible for this modality due to anatomic factors. Apico-Aortic Conduit (AAC) insertion (aortic valve bypass surgery) constitutes a possible option in those patients. Apico-Aortic Conduit is not a new technique, as it has been used for decades in both pediatric and adult populations. However, there is a resurging interest in this technique due to the expanding scope of elderly patients being considered for the treatment of aortic stenosis. Herein, we describe our surgical technique and provide a systematic review of recent publications on AAC insertion, reporting that there is continued use and several modifications of this technique, such as performing it through a small thoracotomy without the use of the cardiopulmonary bypass.

Repeat Cardiac Surgery in a Jehovah's Witness Patient With Thrombocytopenia

Complex cardiac surgery in Jehovahs Witness patients can be challenging, especially if it is a reoperation and the patient has a preexisting bleeding disorder. We operated on a patient who was declined for percutaneous aortic valve replacement and who required repeat surgery for aortic valve repeat replacement and root repair. In addition to being of Jehovahs Witness faith, the patient had chronic thrombocytopenia. We describe our strategy in managing this situation.

Right internal mammary extensive atherosclerosis: a rare incidental finding

Extensive mammary artery atherosclerosis is a rare finding with isolated reports in patients with peripheral vascular disease and after correction of aortic coarctation. The current case represents a rare finding of extensive atherosclerosis in a native right mammary artery in a patient without prior known vasculopathy.