Effect of botulinum toxin on inducibility and maintenance of atrial fibrillation in ovine myocardial tissue.

BACKGROUND: Aberrant vagal stimulation may promote the generation and propagation of atrial fibrillation (AF). Researchers have suggested that botulinum toxin (BTX), a neurotoxin that decreases neural vagal stimulation, may decrease the incidence of postoperative AF. The exact electrophysiologic mechanism underlying the observations and histopathologic alterations associated with BTX are unclear. OBJECTIVE: To investigate the electrophysiologic, functional, and histopathologic effects of BTX on fibrillation induction in ovine atria. METHODS: Eight sheep underwent BTX injections into their pulmonary veins, atrial fat pads, and ventricular walls. Electrophysiology with pacing was performed at baseline and 7 days after injection to evaluate the atrial effective refractory period (ERP) and vulnerability to AF with and without vagal stimulation. Echocardiography was performed at baseline and day 7. After euthanasia, histopathologic analysis was performed. RESULTS: Seven sheep completed the study. For both atria, there was significant shortening in the ERP with vagal stimulation versus no stimulation on day 0 but not on day 7. More aggressive pacing was required to induce AF in the left atrium on day 7 than on day 0. Echocardiography on day 7 showed no significant changes in ejection fraction or new wall-motion abnormalities of the left and right ventricle. Histopathologic analysis showed no significant adverse effects. CONCLUSION: The subacute BTX effect reduced the vulnerability of atrial tissue to AF induction and reduced the vagal influence on atrial ERP shortening compared to baseline levels. Direct BTX injection did not cause myocardial dysfunction or histologic adverse effects.

Association Between Preoperative Aspirin-dosing Strategy and Mortality After Coronary Artery Bypass Graft Surgery.

OBJECTIVE: To determine whether preoperative aspirin-acetylsalicylic acid (ASA)-timing or dose independently affects 30-day all-cause mortality. BACKGROUND: Preoperative ASA administration is associated with reduced morbidity and mortality after coronary artery bypass graft (CABG). However, data are lacking regarding optimal timing and dosing of ASA. METHODS: We retrospectively reviewed data from 3018 consecutive patients who underwent CABG surgery between July 2005 and May 2011. Patients were assigned to 3 groups according to the time of the last preoperative ASA dose: (1) 24 hours or less preoperatively (n = 1173), (2) between 24 and 72 hours (n = 876), and (3) more than 72 hours or none (n = 969). In a separate analysis, patients were grouped according to ASA dose: 81 mg (n = 1285), 325 mg (n = 1004), and none (n = 543). The primary outcome was 30-day all-cause mortality. RESULTS: The 30-day mortality rate was significantly lower in patients who took ASA 24 hours or less preoperatively (1.5%) than in those who took it between 24 and 72 hours (3.2%) or more than 72 hours or none (2.9%). Multivariate analysis showed that ASA within 24 hours preoperatively was associated with reduced mortality (odds ratio [OR], 0.41; 95% confidence interval [CI], 0.20-0.82; P = 0.01). Moreover, mortality was significantly reduced for patients taking 81 mg of ASA (1.4%) compared with 325 mg (2.9%) or none (3.9%). Multivariate analysis demonstrated that 81 mg of ASA decreased mortality risk by 66% (OR, 0.34; 95% CI, 0.18-0.66; P < 0.01), whereas 325 mg of ASA had no mortality benefit (OR, 0.74; 95% CI, 0.41-1.35; P = 0.33) compared with no ASA. CONCLUSIONS: Low-dose ASA use within 24 hours of CABG is independently associated with decreased early postoperative mortality.

Origin of the right coronary artery from the opposite sinus of Valsalva in adults: characterization by intravascular ultrasonography at baseline and after stent angioplasty.

OBJECTIVES: We attempted to characterize the anatomy, function, clinical consequences, and treatment of right-sided anomalous coronary artery origin from the opposite side (R-ACAOS). BACKGROUND: Anomalous aortic origin of a coronary artery is a source of great uncertainty in cardiology. A recent study by our group found that ACAOS had a high prevalence (0.48%) in a general population of adolescents. METHODS: Sixty-seven consecutive patients were diagnosed with R-ACAOS according to a new definition: ectopic right coronary artery (RCA) with an intramural proximal course. We used intravascular ultrasonograms of the RCA to quantify congenital stenosis (in patients with potentially serious clinical presentations), and we correlated these measurements with clinical manifestations. RESULTS: All patients had some proximal intramural stenosis (mean 50%, range 16-83% of the cross-sectional area). Forty-two patients (62%) underwent stent-percutaneous coronary intervention (PCI) of R-ACAOS because of significant symptoms, positive stress tests, and/or significant stenosis. Stent-PCI was successful in all cases and correlated with improved symptoms at >1-year follow-up in 30 patients (71%) who were available for clinical follow-up. No ACAOS-related deaths occurred. The instent restenosis rate was 4/30 (13%) at a mean follow-up time of 5.0 years. CONCLUSIONS: This preliminary, but large and unprecedented observational study shows that cases angiographically identified as R-ACAOS universally feature an intramural aortic course but only occasionally severe stenosis on resting IVUS imaging. Our data suggest that stent-PCI with IVUS monitoring ameliorates patients' presenting symptoms.

Pitfalls in diagnosing ST elevation among patients with acute myocardial infarction.

OBJECTIVES: Patients with ST elevation (STE) in ≥ 2 leads or ST depression (STD) confined to V1-V4 are defined as potential STE myocardial infarction (STEMI). We evaluated the incidence of missed STEMI over an 11-month period. METHODS: Consecutive patients with a discharge diagnosis of non STEMI were retrospectively evaluated. Clinical data, ECG and angiographic data were reviewed. RESULTS: Of the 198 patients screened, 140 were included. Forty-nine patients (35%) met the STEMI criteria: 6 (12%) had STD confined to V1-V3, 20 (41%) had STD in V1-V6, 7 (14%) had STE in V1-V3, 2 (4%) had STE in I and aVL, 11 (22%) had STE in inferior leads, and 6 (12%) had STE in V4-V6. CONCLUSIONS: A significant percentage of patients met STEMI ECG criteria. A large number of patients with STD in V1-V6 had angiographic evidence compatible with inferolateral (posterior) STEMI equivalent.

Body temperature circadian rhythm variability corresponds to left ventricular systolic dysfunction in decompensated cardiomyopathic hamsters.

BACKGROUND: A declining amplitude of body temperature circadian rhythm (BTCR) predicts decompensation or death in cardiomyopathic hamsters. We tested the hypothesis that changes in BTCR amplitude accompany significant changes in left ventricular (LV) size and function. METHODS AND RESULTS: Using intraperitoneal transmitters, we continuously monitored the temperature of 30 male BIO TO-2 Syrian dilated cardiomyopathic hamsters. Cosinor analysis was used to detect significant changes--defined as changes >1 standard deviation from the baseline amplitude for 3 consecutive days--in BTCR amplitude over each hamster's lifespan. The Student t-test was used to compare BTCR variability and LV size and function (as assessed by 2D echocardiography) between baseline and the time that BTCR amplitude declined. All hamsters received 10 mg/kg furosemide daily. At the time of BTCR amplitude decline, functional parameters had changed significantly (P < .0001) from baseline: ejection fraction (0.31 ± 0.09% vs. 0.52 ± 0.08%), LV end-systolic volume (0.11 ± 0.03 vs. 0.05 ± 0.02 cm(3)), and LV end-diastolic volume (0.16 ± 0.04 vs. 0.10 ± 0.03 cm(3)). CONCLUSIONS: In decompensated cardiomyopathic hamsters, a decline in BTCR amplitude was associated with progression of heart failure and cardiac decompensation. Variation in BTCR warrants further investigation because of its potential implications for the diagnosis and treatment of cardiovascular disorders.

Prognostic significance of delayed-enhancement magnetic resonance imaging: survival of 857 patients with and without left ventricular dysfunction.

BACKGROUND: Left ventricular ejection fraction is a powerful independent predictor of survival in cardiac patients, especially those with coronary artery disease. Delayed-enhancement magnetic resonance imaging (DE-MRI) can accurately identify irreversible myocardial injury with high spatial and contrast resolution. To date, relatively limited data are available on the prognostic value of DE-MRI, so we sought to determine whether DE-MRI findings independently predict survival. METHODS AND RESULTS: The medical records of 857 consecutive patients who had complete cine and DE-MRI evaluation at a tertiary care center were reviewed regardless of whether the patients had coronary artery disease. The presence and extent of myocardial scar were evaluated qualitatively by a single experienced observer. The primary, composite end point was all-cause mortality or cardiac transplantation. Survival data were obtained from the Social Security Death Index. The median follow-up was 4.4 years; 252 patients (29%) reached one of the end points. Independent predictors of mortality or transplantation included congestive heart failure, ejection fraction, and age (P<0.0001 for each), as well as scar index (hazard ratio, 1.26; 95% confidence interval, 1.02 to 1.55; P=0.033). Similarly, in subsets of patients with or without coronary artery disease, scar index also independently predicted mortality or transplantation (hazard ratio, 1.33; 95% confidence interval, 1.05 to 1.68; P=0.018; and hazard ratio, 5.65; 95% confidence interval, 1.74 to 18.3; P=0.004, respectively). Cox regression analysis showed worse outcome in patients with any DE in addition to depressed left ventricular ejection fraction (<50%). CONCLUSIONS: The degree of DE detected by DE-MRI appears to strongly predict all-cause mortality or cardiac transplantation after adjustment for traditional, well-known prognosticators.

Circadian body temperature variability is an indicator of poor prognosis in cardiomyopathic hamsters.

BACKGROUND: Low body temperature is an independent predictor of poor prognosis in patients with congestive heart failure. The cardiomyopathic hamster develops progressive biventricular dysfunction, resulting in heart failure death at 9 months to 1 year of life. Our goal was to use cardiomyopathic hamsters to examine the relationship between body temperature and heart failure decompensation and death. METHODS AND RESULTS: To this end, we implanted temperature and activity transducers with telemetry into the peritoneal space of 46 male Bio-TO-2 Syrian cardiomyopathic hamsters. Multiple techniques, including computing mean temperature, frequency domain analysis, and nonlinear analysis, were used to determine the most useful method for predicting poor prognosis. Data from 44 hamsters were included in our final analysis. We detected a decline in core body temperature in 98% of the hamsters 8+/-4 days before death (P < .001). We examined the dominant frequency of temperature variation (ie, the circadian rhythm) by using cosinor analysis, which revealed a significant decrease in the amplitude of the body temperature circadian rhythm 8 weeks before death (0.28 degrees C; 95% CI, 0.26-0.31) compared to baseline (0.36 degrees C; 95% CI, 0.34-0.39; P=.005). The decline in the circadian temperature variation preceded all other evidence of decompensation. CONCLUSIONS: We conclude that a decrease in the amplitude of the body temperature circadian rhythm precedes fatal decompensation in cardiomyopathic hamsters. Continuous temperature monitoring may be useful in predicting preclinical decompensation in patients with heart failure and in identifying opportunities for therapeutic intervention.

Predicting major adverse cardiac events after percutaneous coronary intervention: the Texas Heart Institute risk score.

BACKGROUND: Many models have been devised in the past to predict adverse outcomes after PCI, but with rapid advancements in this field, a new risk-prediction model may be needed. The purpose of our study was to identify the clinical and angiographic variables associated with adverse cardiac events after percutaneous coronary intervention (PCI) and to construct a simple bedside tool for risk stratification of PCI patients. METHODS: Using our institution's database, we analyzed data from 9,494 patients who underwent PCI between January 1, 1996, and December 31, 2002 (ie, during the bare-metal stent era). Predictors of major adverse cardiac events--death, myocardial infarction, stroke, and repeat revascularization by emergent coronary artery bypass grafting or PCI--were identified by multivariate logistic regression analysis using baseline clinical, angiographic, and procedural variables. A simple integer score was constructed by multiplying the beta coefficient for each variable by a constant and rounding the result to the nearest integer. The score was validated in 5,545 patients who underwent PCI between January 1, 2003, and December 31, 2006 (ie, during the drug-eluting stent era). RESULTS: Multivariate regression analysis identified emergent procedure, urgent procedure, unstable angina, acute myocardial infarction, renal insufficiency, hypertension, congestive heart failure, peripheral vascular disease, type C lesion, presence of thrombus, and number of stents placed as independent predictors of adverse events after PCI. The model had good overall discrimination (area under the receiver operator characteristic curve 0.701), and the model fitted the validation cohort adequately. CONCLUSIONS: Risk of complications after PCI can be assessed with this simple tool, which may permit comparisons between different operators as well as different hospitals.

Risk stratification after successful coronary revascularization.

BACKGROUND: Clinicians treating coronary revascularization patients need to be able to identify those who require more intensive medical therapy or follow-up. However, predictors of survival after coronary revascularization are often reported in terms of hazard ratios, which are accurate but difficult to convert to concrete values. We sought to develop a more practical and user-friendly method of predicting long-term survival in revascularization patients. METHODS: We used a decision-tree induction algorithm to retrospectively examine all-cause mortality during 3-year follow-up in 3331 consecutive patients with multivessel or single proximal left anterior descending coronary artery disease who underwent an isolated first revascularization by either coronary stenting or coronary artery bypass graft between 1995 and 1999. RESULTS: Recursive partitioning of the derivation cohort by the algorithm indicated that the best single predictor of long-term mortality was history of congestive heart failure, followed by age greater than 65 years and the presence of renal insufficiency. With these three variables, patients were readily stratified into low-, intermediate-, and high-risk groups whose 3-year mortality risks ranged from 2.0% to 18.8%. Logistic regression revealed nine significant predictors of 3-year mortality, including two interaction terms. Areas under the receiver operation characteristic curve for prediction of 3-year mortality were not significantly different between the decision tree and the logistic regression models [0.72 (95% confidence interval, 0.69 to 0.75) vs. 0.76 (95% confidence interval, 0.73 to 0.80)]. CONCLUSIONS: Long-term mortality risk in coronary revascularization patients can be estimated from three predictors that are easily obtained in clinical settings.

Effect of Dose and Timing of Preoperative Statins on Mortality After Coronary Artery Bypass Surgery.

BACKGROUND: Preoperative statin administration is associated with reduced mortality risk after a coronary artery bypass graft operation. However, the optimal dose and timing are unknown. METHODS: We retrospectively reviewed data from 3,025 primary isolated coronary artery bypass graft surgery patients at our institution. Patients were divided into three groups, according to timing of their preoperative statin: 24 hours or less (n = 1,788), 24 to 72 hours (n = 452), or more than 72 hours before operation or no dose (n = 781). We then grouped patients by preoperative dose: no statin (n = 739), 20 mg or less (n = 920), or more than 20 mg (n = 1,284) atorvastatin or equivalent. Primary outcome was 30-day all-cause postoperative mortality. RESULTS: Thirty-day all-cause mortality was significantly lower for patients taking a statin 24 hours or less preoperatively (1.7%) compared with 24 to 72 hours (2.9%), more than 72 hours, or no dose (3.8%). Multivariate analysis of a propensity-matched cohort showed taking statins 24 hours or less preoperatively was associated with reduced 30-day all-cause mortality (odds ratio 0.52, 95% confidence interval: 0.28 to 0.98, p = 0.04) versus more than 24 hours or no dose. For preoperative statin dose, 30-day all-cause mortality was significantly lower when taking 20 mg or less(1.8%) or more than 20 mg atorvastatin or equivalent (2.1%) than when taking none (3.8%). In multivariate analysis of the propensity-matched cohort, more than 20 mg preoperative dose was associated with a 68% reduction of 30-day all-cause mortality (odds ratio 0.32, 95% confidence interval: 0.13 to 0.82, p = 0.02) compared with no preoperative statin. However, a 20 mg or less preoperative dose showed no mortality reduction. CONCLUSIONS: Both statin use 24 hours or less preoperatively and preoperative statin dose of more than 20 mg were independently associated with decreased 30-day all-cause mortality after coronary artery bypass graft surgery.

Comparative Efficacy of Nebivolol and Metoprolol to Prevent Tachycardia-Induced Cardiomyopathy in a Porcine Model.

Chronic tachycardia is a well-known cause of nonischemic cardiomyopathy. We hypothesized that nebivolol, a ß-blocker with nitric oxide activity, would be superior to a pure ß-blocker in preventing tachycardia-induced cardiomyopathy in a porcine model. Fifteen healthy Yucatan pigs were randomly assigned to receive nebivolol, metoprolol, or placebo once a day. All pigs underwent dual-chamber pacemaker implantation. The medication was started the day after the pacemaker implantation. On day 7 after implantation, each pacemaker was set at atrioventricular pace (rate, 170 beats/min), and the pigs were observed for another 7 weeks. Transthoracic echocardiograms, serum catecholamine levels, and blood chemistry data were obtained at baseline and at the end of the study. At the end of week 8, the pigs were euthanized, and complete histopathologic studies were performed. All the pigs developed left ventricular cardiomyopathy but remained hemodynamically stable and survived to the end of the study. The mean left ventricular ejection fraction decreased from baseline by 34%, 20%, and 20% in the nebivolol, metoprolol, and placebo groups, respectively. These changes did not differ significantly among the 3 groups (P =0.51). Histopathologic analysis revealed mild left ventricular perivascular fibrosis with cardiomyocyte hypertrophy in 14 of the 15 pigs. Both nebivolol and metoprolol failed to prevent cardiomyopathy in our animal model of persistent tachycardia and a high catecholamine state.

[Preoperative patient education: can we improve satisfaction and reduce anxiety?]. / Informação pré-operatória ao paciente: podemos melhorar a satisfação e reduzir a ansiedade?

BACKGROUND AND OBJECTIVES: Patients' knowledge deficits concerning anesthesia and the anesthesiologist's role in their care may contribute to anxiety. The objective of this study was to develop anesthesia patient education materials that would help improve patient's satisfaction regarding their knowledge of the perioperative process and decrease anxiety in a community hospital with a large Spanish-speaking population. METHODS: A survey (Survey A) in English and Spanish was administered to all adult anesthesiology preoperative clinic patients during a 4-week period. The data were analyzed and then a patient education handout was developed in both English and Spanish to assist with our patients' major concerns. A second survey (Survey B) was administered that was completed after the education handout had been put into use at the clinic. The survey asked for basic demographic information and included questions on satisfaction with regard to understanding of anesthesia as well as worries regarding surgery and pain. RESULTS: In the patients who received the handout, statistically significant improvement was found in the questions that asked about satisfaction with regard to understanding of type of anesthesia, options for pain control, what patients are supposed to do on the day of surgery, and the amount of information given with regard to anesthetic plan. There was no difference in anxiety related to surgery in patients who received the educational handout compared to those patients who did not. CONCLUSIONS: Patient education handouts improved patient's satisfaction regarding their knowledge of the perioperative process but did not reduce anxiety related to surgery.

Protocol-Driven Allied Health Post-Discharge Transition Clinic to Reduce Hospital Readmissions in Heart Failure.

BACKGROUND: Heart failure (HF) patients have high rates of hospitalization and rehospitalization. METHODS AND RESULTS: A protocol-driven clinic staffed by an allied health care team was designed for patients discharged from the hospital with a diagnosis of congestive HF. The clinic provided follow-up visits 1 week and 4 to 6 weeks after hospital discharge. One-hundred and fourteen patients were observed at least 1 time, and 80% of these patients completed the 2-visit protocol. Clinical evaluations were provided by a nurse practitioner specializing in HF and a clinical pharmacist; these evaluations included physical examination, laboratory evaluation, medical education and reconciliation, medication adjustment and titration, and care coordination. Referrals to home health and appropriate services were provided. At visit 1, 25% of patients were hypervolemic and 13% were hypovolemic. At visit 2, 20% were hypervolemic and 13% were hypovolemic. Medicine reconciliation errors were common, with an average of 2.1 and 0.8 errors per person recorded for visits 1 and 2, respectively. Clinic participants showed a 44.3% reduction in 30-day readmission rates, as compared to the hospital's average 30-day readmission rates. CONCLUSIONS: Protocol-driven postdischarge transition care delivered by allied health staff addressed multiple transition issues and was associated with a dramatic reduction in readmission rates.

Present-Day Hospital Readmissions after Left Ventricular Assist Device Implantation: A Large Single-Center Study.

Left ventricular assist device (LVAD) therapy improves survival, hemodynamic status, and end-organ perfusion in patients with refractory advanced heart failure. Hospital readmission is an important measure of the intensity of LVAD support care. We analyzed readmissions of 148 patients (mean age, 53.6 ± 12.7 yr; 83% male) who received a HeartMate II LVAD from April 2008 through June 2012. The patients had severe heart failure; 60.1% were in Interagency Registry for Mechanically Assisted Circulatory Support class 1 or 2. All patients were observed for at least 12 months, and readmissions were classified as planned or unplanned. Descriptive and multivariate regression analyses were used to identify predictors of unplanned readmission. Twenty-seven patients (18.2%) had no readmissions or 69 planned readmissions, and 121 patients (81.8%) had 460 unplanned readmissions. The LVAD-related readmissions were for bleeding, thrombosis, and anticoagulation (n=103; 49.1%), pump-related infections (n=60; 28.6%), and neurologic events (n=28; 13.3%). The readmission rate was 2.1 per patient-year. Unplanned readmissions were for comorbidities and underlying cardiac disease (54.3%) or LVAD-related causes (45.7%). In the unplanned-readmission rate, there was no significant difference between bridge-to-transplantation and destination-therapy patients. Unplanned readmissions were associated with diabetes mellitus (odds ratio [OR]=3.3; P=0.04) and with shorter mileage from residence to hospital (OR=0.998; P=0.046). Unplanned admissions for LVAD-related sequelae and ongoing comorbidities were common. Diabetes mellitus and shorter distance from residence to hospital were significant predictors of readmission. We project that improved management of comorbidities and of anticoagulation therapy will reduce unplanned readmissions of LVAD patients in the future.

Coronary artery bypass surgery versus coronary stenting: risk-adjusted survival rates in 5,619 patients.

We used the Texas Heart Institute Cardiovascular Research Database to retrospectively identify patients who had undergone their 1st revascularization procedure with coronary artery bypass surgery (CABG; n=2,826) or coronary stenting (n=2,793) between January 1995 and December 1999. Patients were classified into 8 anatomic groups according to the number of diseased vessels and presence or absence of proximal left anterior descending coronary artery disease. Mortality rates were adjusted with proportional hazards methods to correct for baseline differences in severity of disease and comorbidity. We found that in-hospital mortality was significantly greater in patients undergoing CABG than in those undergoing stenting (3.6% vs 0.75%; adjusted OR 8.4; P < 0.0001). At a mean 2.5-year follow-up, risk-adjusted survival was equivalent (CABG 91%, stenting 95%; adjusted OR 1.26; P = 0.06). When subgroups matched for severity of disease were compared, no differences in risk-adjusted survival were seen. A survival advantage of stenting was noted in 3 categories of patients: those >65 years of age (OR 1.33, P = 0.049), those with non-insulin-requiring diabetes (OR 2.06, P = 0.002), and those with any noncoronary vascular disease (OR 1.59, P = 0.009). In this nonrandomized observational study, CABG had a higher periprocedural mortality rate than did percutaneous stenting. At 2.5 years, however, the survival advantage of stenting was no longer evident. These data suggest that there is no intermediate-term survival advantage of CABG over stenting in patients who have multivessel disease with lesions that can be treated percutaneously.

Low serum sodium level during cardiopulmonary bypass predicts increased risk of postoperative stroke after coronary artery bypass graft surgery.

OBJECTIVE: Rapid decreases in serum sodium levels are associated with altered mental status, seizures, and coma. During cardiac surgery, serum sodium levels decrease rapidly when cardiopulmonary bypass is initiated because cardiopulmonary bypass causes hemodilution. However, whether this decrease influences neurologic outcome after cardiac surgery remains unclear. We investigated whether the average serum sodium level during cardiopulmonary bypass is independently predictive of postoperative stroke or 30-day all-cause mortality in patients who undergo primary coronary artery bypass grafting. METHODS: In a single-institution, retrospective cohort of 2348 consecutive patients who underwent primary, isolated coronary artery bypass grafting, sequential multivariate logistic regression was performed to determine the threshold below which the average serum sodium level during cardiopulmonary bypass independently predicts postoperative stroke or early death. To further test the validity of this threshold and to control for selection bias, stepwise multivariate logistic regression was also performed on propensity score-matched patients (n = 924). RESULTS: An average serum sodium level less than 130 mEq/L during cardiopulmonary bypass was independently predictive of stroke, both in the entire study cohort (1.44% vs 2.92%; odds ratio, 2.09; 95% confidence interval, 1.1-4.1; P = .03) and in the propensity-matched patients (0.9% vs 3.0%; odds ratio, 4.1; 95% confidence interval, 1.3-13.0; P = .02). The average serum sodium level during cardiopulmonary bypass was not independently associated with early death, regardless of what threshold value was used. CONCLUSIONS: An average serum sodium level of less than 130 mEq/L during cardiopulmonary bypass is independently associated with an increased risk of postoperative stroke in patients who undergo primary coronary artery bypass grafting.

Predicting early death after cardiovascular surgery by using the Texas Heart Institute Risk Scoring Technique (THIRST).

Preoperative risk-prediction models are an important tool in contemporary surgical practice. We developed a risk-scoring technique for predicting in-hospital death for cardiovascular surgery patients. From our institutional database, we obtained data on 21,120 patients admitted from 1995 through 2007. The outcome of interest was early death (in-hospital or within 30 days of surgery). To identify mortality predictors, multivariate logistic regression was performed on data from 14,030 patients from 1995 through 2002 and risk scores were computed to stratify patients (low-, medium-, and high-risk). A recalibrated model was then created from the original risk scores and validated on data from 7,090 patients from 2003 through 2007. Significant predictors of death included urgent surgery within 48 hours of admission, advanced age, renal insufficiency, repeat coronary artery bypass grafting, repeat aortic aneurysm repair, concomitant aortic aneurysm or left ventricular aneurysm repair with coronary bypass or valvular surgery, and preoperative intra-aortic balloon pump support. Because the original model overpredicted death for operations performed from 2003 through 2007, this was adjusted for by applying the recalibrated model. Applying the recalibrated model to the validation set revealed predicted mortality rates of 1.7%, 4.2%, and 13.4% and observed rates of 1.1%, 5.1%, and 13%, respectively. Because our model discriminates risk groups by using preoperative clinical criteria alone, it can be a useful bedside tool for identifying patients at greater risk of early death after cardiovascular surgery, thereby facilitating clinical decision-making. The model can be recalibrated for use in other types of patient populations.

Preventing sudden cardiac death in athletes: in search of evidence-based, cost-effective screening.

Sudden cardiac death in athletes is a recurrent phenomenon at sporting events and during training. Recent studies have associated sudden cardiac death with such cardiovascular conditions as coronary artery anomalies, cardiomyopathies, and electrocardiographic abnormalities, most of which are screenable with modern imaging techniques. We recently inaugurated the Center for Coronary Artery Anomalies at the Texas Heart Institute, which is dedicated to preventing sudden cardiac death in the young and investigating coronary artery anomalies. There, we are conducting 2 cross-sectional studies intended to firmly establish and quantify, in a large group of individuals from a general population, risk factors for sudden cardiac death that arise from specific cardiovascular conditions. In a pilot screening study, we are using a brief, focused clinical questionnaire, electrocardiography, and a simplified novel cardiovascular magnetic resonance screening protocol in approximately 10,000 unselected 11- to 15-year-old children. Concurrently, we are prospectively studying the prevalence of these same conditions, their severity, and their relation to exercise and mode of death in approximately 6,500 consecutive necropsy cases referred to a large forensic center. Eventually, we hope to use our findings to develop a more efficient method of preventing sudden cardiac death in athletes. We believe that these studies will help quantify sudden cardiac death risk factors and the relevance of associated physical activities--crucial information in evaluating the feasibility and affordability of cardiovascular magnetic resonance-based screening. We discuss the rationale for and methods of this long-term endeavor, in advance of reporting the results.

Moderate hypothermia during aortic arch surgery is associated with reduced risk of early mortality.

OBJECTIVE: Selective antegrade cerebral perfusion (ACP) during hypothermic circulatory arrest (HCA) provides cerebral protection during aortic arch surgery. However, the ideal temperature for HCA during ACP remains unknown. Clinical outcomes were compared in patients who underwent moderate (nasopharyngeal temperature, ≥ 20 °C) versus deep (nasopharyngeal temperature, <20 °C) HCA with ACP during aortic arch repair. METHODS: By using a prospectively maintained clinical database, we analyzed data from 221 consecutive patients who underwent aortic arch replacement with HCA and ACP between December 2006 and May 2009. Seventy-eight patients underwent deep hypothermia (mean lowest temperature, 16.8 °C ± 1.7 °C) and 143 patients underwent moderate hypothermia (mean, 22.9 °C ± 1.4 °C) before systemic circulatory arrest was initiated. Multivariate stepwise logistic and linear regressions were performed to determine whether depth of hypothermia independently predicted postoperative outcomes and blood-product use. RESULTS: Compared with moderate hypothermia, deep hypothermia was associated independently with a greater risk of in-hospital death (7.7% vs 0.7%; odds ratio [OR], 9.3; 95% confidence interval [CI], 1.1-81.6; P = .005) and 30-day all-cause mortality (9.0% vs 2.1%; OR, 4.7; 95% CI, 1.2-18.6; P = .02), and with longer cardiopulmonary bypass time (154 ± 62 vs 140 ± 46 min; P = .008). Deep hypothermia also was associated with a higher incidence of stroke, although this association was not statistically significant (7.6% vs 2.8%; P = .073; OR, 4.3; 95% CI, 0.9-12.5). No difference was seen in acute kidney injury, blood product transfusion, or need for surgical re-exploration. CONCLUSIONS: Moderate hypothermia with ACP is associated with lower in-hospital and 30-day mortality, shorter cardiopulmonary bypass time, and fewer neurologic sequelae than deep hypothermia in patients who undergo aortic arch surgery with ACP.