Faculty Bibliography

The aim was to investigate the association between continuing angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARB) with postinduction hypotension and vasoactive drug use in elderly orthopedic surgery patients under regional anesthesia. Retrospective design consisted of 114 patients (mean age 66) undergoing elective total knee arthroplasty, including 84 patients with chronic hypertension, and they were divided as group I (n = 37), ACEI/ARB continued; group II (n = 23), ACEI/ARB withdrawn; group III (n = 24), β-blocker/calcium channel blocker continued; and group IV (n = 30), without hypertension (control). Primary end points are systolic blood pressures (SBPs) and mean arterial blood pressures (MAPs) at 0, 30, 60, and 90 minutes postinduction, incidence of hypotension (SBP <85 mm Hg), and ephedrine requirements. Repeated measurements were analyzed using generalized estimating equations controlling for baseline characteristics and accounting for correlations. Logistic regression was used for remaining variables. Hypotension occurred more frequently (P = .02) in group I (30%) versus groups II-IV (9%, 13%, 3%). Ephedrine use was increased (P < .001) in group I (51%) compared with groups II-IV (26%, 17%, 7%). Group I had lower mean SBPs compared with group II (110 vs. 120; P = .0045) and group IV (110 vs. 119; P = .0013). Lower mean MAPs were found in group I versus group II (74 vs. 81, P = .001) and group IV (74 vs. 80; P = .001). Group I had an increased odds of receiving ephedrine versus group IV (odds ratio, 16.27; 95% confidence interval, 3.10-85.41; P = .001). No adverse clinical events were recorded. Day of surgery ACEI/ARB use is associated with a high incidence and severity of postinduction hypotension with associated high vasopressor requirements. Associated clinical outcomes merit further study.

The management of perioperative cardiovascular risk in patients with rheumatoid arthritis (RA) is challenging due to the independent contribution to risk by high grade inflammatory mechanisms and the underestimation of risk by traditional cardiac risk factors alone. RA is associated with accelerated rates of subclinical atherosclerosis and markedly higher rates of both myocardial infarction and sudden cardiac death over non-RA controls. There is an absence of prospectively validated perioperative coronary heart disease (CHD) risk assessment tools for this unique patient population and available guidelines may fail to identify those patients most at risk. We examine a singular case of first time myocardial infarction after uncomplicated elective surgery in an adult RA patient with an unrevealing preoperative cardiac assessment. We also review the current literature for shared pathogenic mechanisms between systemic inflammation and atherosclerosis, discuss clinical and biologic markers such as C-reactive protein (CRP) in RA patients associated with heightened cardiac risk and discuss recommendations based on available evidence for cardiovascular risk management in this at risk cohort.

Angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor antagonists (ARA) are effective and well-tolerated first-line drugs in the therapy of hypertension and, therefore, are frequently encountered in the perioperative setting. Hemodynamic compensation for volume depletion seen in the perioperative period is normally mediated by the renin-angiotensin system, which is blocked by ACEI/ARA. These drugs may contribute to severe hypotension during anesthesia induction and may have contributed to the cardiac arrest seen in this patient. Additional factors such as increased intra-abdominal pressures and respiratory obstructive episodes leading to diminished venous return, as well diuretic use and the fasting state, common in the perioperative orthopedic patient, are likely to have contributed as well. Medication use may be an easily modifiable risk factor for severe hypotension and possible cardiac arrest in the perioperative setting.

OBJECTIVES/OBJECTIVE:This study sought to compare contrast-enhanced anatomic imaging and contrast-enhanced tissue characterization (delayed-enhancement cardiac magnetic resonance [DE-CMR]) for left ventricular (LV) thrombus detection. BACKGROUND:Contrast echocardiography (echo) detects LV thrombus based on anatomic appearance, whereas DE-CMR imaging detects thrombus based on tissue characteristics. Although DE-CMR has been validated as an accurate technique for thrombus, its utility compared with contrast echo is unknown. METHODS:Multimodality imaging was performed in 121 patients at high risk for thrombus due to myocardial infarction or heart failure. Imaging included 3 anatomic imaging techniques for thrombus detection (contrast echo, noncontrast echo, cine-CMR) and a reference of DE-CMR tissue characterization. LV structural parameters were quantified to identify markers for thrombus and predictors of additive utility of contrast-enhanced thrombus imaging. RESULTS:Twenty-four patients had thrombus by DE-CMR. Patients with thrombus had larger infarcts (by DE-CMR), more aneurysms, and lower LV ejection fraction (by CMR and echo) than those without thrombus. Contrast echo nearly doubled sensitivity (61% vs. 33%, p < 0.05) and yielded improved accuracy (92% vs. 82%, p < 0.01) versus noncontrast echo. Patients who derived incremental diagnostic utility from DE-CMR had lower LV ejection fraction versus those in whom noncontrast echo alone accurately assessed thrombus (35 +/- 9% vs. 42 +/- 14%, p < 0.01), with a similar trend for patients who derived incremental benefit from contrast echo (p = 0.08). Contrast echo and cine-CMR closely agreed on the diagnosis of thrombus (kappa = 0.79, p < 0.001). Thrombus prevalence was lower by contrast echo than DE-CMR (p < 0.05). Thrombus detected by DE-CMR but not by contrast echo was more likely to be mural in shape or, when apical, small in volume (p < 0.05). CONCLUSIONS:Echo contrast in high-risk patients markedly improves detection of LV thrombus, but does not detect a substantial number of thrombi identified by DE-CMR tissue characterization. Thrombi detected by DE-CMR but not by contrast echo are typically mural in shape or small in volume.

Several biomarkers have been documented, singly or jointly, to improve risk prediction, but the extent to which they improve prediction-model performance in populations with high prevalences of obesity and diabetes has not been specifically examined. The aim of this study was to evaluate the ability of various biomarkers to improve prediction-model performance for death and major cardiovascular disease (CVD) events in a high-risk population. The relations of 6 biomarkers with outcomes were examined in 823 American Indians free of prevalent CVD or renal insufficiency, as were their contributions to risk prediction. In single-marker models adjusting for standard clinical and laboratory risk factors, 4 of 6 biomarkers significantly predicted mortality and major CVD events. In multimarker models, these 4 biomarkers-urinary albumin/creatinine ratio (UACR), glycosylated hemoglobin, B-type natriuretic peptide, and fibrinogen-significantly predicted mortality, while 2-UACR and fibrinogen-significantly predicted CVD. On the basis of its robust association in participants with diabetes, UACR was the strongest predictor of mortality and CVD, individually improving model discrimination or classification in the entire cohort. Singly, all remaining biomarkers also improved risk classification for mortality and enhanced average sensitivity for mortality and CVD. The addition of > or =1 biomarker to the single marker UACR further improved discrimination or average sensitivity for these outcomes. In conclusion, biomarkers derived from diabetic cohorts, and novel biomarkers evaluated primarily in lower risk populations, improve risk prediction in cohorts with prevalent obesity and diabetes. Risk stratification of these populations with multimarker models could enhance selection for aggressive medical or surgical approaches to prevention.

Despite widespread testing, the utility of aminoterminal pro-brain natriuretic peptide (NT-pro-BNP) for diagnosis or risk assessment in patients with diabetes mellitus (DM) in the emergency department (ED) remains unclear. NT-pro-BNP was measured in subjects with dyspnea in the ED. A final diagnosis of acute heart failure (HF) was determined by blinded study physicians using all available hospital records. Vital status was assessed at 1 year; independent predictors of death were identified using Cox analysis. Of 599 subjects, 157 (26.2%) had DM, which was an independent predictor of a final diagnosis of acute HF. In patients diagnosed with acute HF, median concentrations of NT-pro-BNP were similar in patients with and without DM (4,784 vs 3,382 pg/ml, respectively, p = 0.93). In dyspneic subjects without acute HF, median concentrations of NT-pro-BNP were significantly higher in patients with DM (242 vs 115 pg/ml, p = 0.01), but this difference was no longer significant after adjusting for relevant covariates. The area under the curve for NT-pro-BNP to diagnose acute HF in subjects with DM was 0.94 (p <0.001). Using age-adjusted cutpoints, NT-pro-BNP was 92% sensitive and 90% specific for the diagnosis of HF in diabetic subjects. In diabetic patients, a NT-pro-BNP level > or =986 pg/ml was independently associated with an increased risk of death at 1 year (hazard ratio 3.42, 95% confidence interval 1.09 to 10.7, p <0.001). In conclusion, NT-pro-BNP testing offers valuable diagnostic and prognostic information in the evaluation of dyspneic patients with DM in the ED, using identical cutpoints as the population as whole.

Among patients that present with cardiac masses, thrombus is an important diagnostic consideration that affects both clinical management and prognosis. Although thrombus can occasionally be difficult to diagnose using structural criteria alone, it can be distinguished from other structures according to tissue characteristics. Because thrombus is inherently avascular, absence of contrast uptake was used as a highly specific identifying feature. Delayed-contrast cardiac computed tomography (CT) imaging has been previously used for myocardial tissue characterization, distinguishing between viable and infarcted myocardium based upon differences in contrast uptake. This technique also offers potential diagnostic utility for assessment of thrombus. In this report, we describe a case of a patient with a giant left atrial mass in whom delayed-contrast CT was employed as a useful diagnostic technique for identification of cardiac thrombus.

BACKGROUND:Amino-terminal pro-brain natriuretic peptide (NT-proBNP) is useful for the diagnosis and exclusion of congestive heart failure (HF). Little is known about the effect of race on NT-proBNP concentrations. Also, NT-proBNP levels may be higher in apparently well women, but the effect of gender on NT-proBNP concentrations in dyspneic patients is not known. METHODS AND RESULTS/RESULTS:NT-proBNP (Elecsys proBNP, Roche, Indianapolis, IN) was measured in 599 dyspneic patients in a prospective study. Of these, 44 were African American; 295 were female. NT-proBNP levels were examined according to race and gender in patients with and without acute HF using analysis of covariance. Receiver operating characteristic (ROC) curves assessed NT-proBNP by race and gender. Cutpoints for diagnosis (450, 900, and 1800 pg/mL for ages < 50, 50 to 75, and > 75 years) and exclusion (300 pg/mL) were examined in African-American and female subjects. There was no difference in the rates of acute HF between African-American and non-African-American (30% versus 35%, P = .44) or male and female (35% versus 35%, P = .86) subjects. In subjects with HF, there was no difference in median NT-proBNP concentrations between African American and non-African American (6196 versus 3597 pg/mL, P = .37). In subjects without HF, unadjusted NT-proBNP levels were lower in African-American subjects than in non-African-American subjects (68 versus 148 pg/mL, P < .03); however, when adjusted for factors known to influence NT-proBNP concentrations (age, prior HF, creatinine clearance, atrial fibrillation, and body mass index), race no longer significantly affected NT-proBNP concentrations. There was no statistical difference in median NT-proBNP concentrations between male and female subjects with (4686 versus 3622 pg/mL, P = .53) or without HF (116 pg/mL versus 150 pg/mL, P = .62). Among African Americans, NT-proBNP had an area under the ROC for acute HF of 0.96 (P < .0001), and at optimal cutpoints, had a sensitivity of 100% and a specificity of 90%. Among females, NT-proBNP had an area under the ROC for acute HF of 0.95 (P < .0001), and had a sensitivity of 89% and a specificity of 88%; 300 pg/mL had negative predictive value of 100% in African Americans and females. CONCLUSION/CONCLUSIONS:NT-proBNP is useful for the diagnosis and exclusion of acute HF in dyspneic subjects, irrespective of race or gender.

Left ventricular hypertrophy (LVH) is a strong, independent predictor of cardiovascular events and all-cause mortality. Patients with LVH are at increased risk for stroke, coronary heart disease, congestive heart failure, and sudden cardiac death. Hypertension is a major influence on the development of LVH. The prognostic power of LVH is likely multifactorial. LVH represents both a manifestation of the effects of hypertension and other cardiac risk factors over time as well as an intrinsic condition causing pathologic changes in cardiac structure and function. Angiotensin II plays a central role in the development of LVH. Several antihypertensive treatments, especially angiotensin II receptor blockers, can reverse LVH and improve cardiovascular outcomes independent of blood pressure reduction. Further studies are required to determine if these agents should become first-line therapy for all patients with hypertension and LVH.