Kenneth A. Brown

ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery: Executive summary - A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (writing committee to revise the 2002 guidelines on perioperative cardiovascular evaluation for noncardiac surgery)

WRITING COMMITTEE MEMBERS Lee A. Fleisher, MD, FACC, FAHA, Chair; Joshua A. Beckman, MD, FACC¶; Kenneth A. Brown, MD, FACC, FAHA†; Hugh Calkins, MD, FACC, FAHA‡; Elliot L. Chaikof, MD#; Kirsten E. Fleischmann, MD, MPH, FACC; William K. Freeman, MD, FACC*; James B. Froehlich, MD, MPH, FACC; Edward K. Kasper, MD, FACC; Judy R. Kersten, MD, FACC§; Barbara Riegel, DNSc, RN, FAHA; John F. Robb, MD, FACC

Characterization of the Peri-Infarct Zone by Contrast-Enhanced Cardiac Magnetic Resonance Imaging Is a Powerful Predictor of Post–Myocardial Infarction Mortality

Background— Accurate risk stratification is crucial for effective treatment planning after myocardial infarction (MI). Previous studies suggest that the peri-infarct border zone may be an important arrhythmogenic substrate. In this pilot study, we tested the hypothesis that the extent of the peri-infarct zone quantified by contrast-enhanced cardiac magnetic resonance (CMR) is an independent predictor of post-MI mortality. Methods and Results— We studied 144 patients with documented coronary artery disease and abnormal myocardial delayed enhancement (MDE) consistent with MI. A computer-assisted, semiautomatic algorithm quantified the total infarct size and divided it into the core and peri-infarct regions based on signal-intensity thresholds (>3 SDs and 2 to 3 SDs above remote normal myocardium, respectively). The peri-infarct zone was normalized as a percentage of the total infarct size (%MDEperiphery). After a median follow-up of 2.4 years, 29 (20%) patients died. Patients with an above-median %MDEperiphery were at higher risk for death compared with those with a below-median %MDEperiphery (28% versus 13%, log-rank P<0.01). Multivariable analysis showed that left ventricular systolic volume index and %MDEperiphery were the strongest predictors of all-cause mortality (adjusted hazard ratio [HR] for %MDEperiphery, 1.45 per 10% increase; P=0.002) and cardiovascular mortality (adjusted HR, 1.51 per 10% increase; P=0.009). Similarly, after adjusting for age and left ventricular ejection fraction, %MDEperiphery maintained strong and independent associations with all-cause mortality (adjusted HR, 1.42; P=0.005) and cardiovascular mortality (adjusted HR, 1.49; P=0.01). Conclusions— In patients with a prior MI, the extent of the peri-infarct zone characterized by CMR provides incremental prognostic value beyond left ventricular systolic volume index or ejection fraction. Infarct characteristics by CMR may prove to be a unique and valuable noninvasive predictor of post-MI mortality.

Impact of Unrecognized Myocardial Scar Detected by Cardiac Magnetic Resonance Imaging on Event-Free Survival in Patients Presenting With Signs or Symptoms of Coronary Artery Disease

Background— Contrast-enhanced cardiac magnetic resonance imaging (CMR) can determine the extent of myocardial scar from infarction (MI). However, the prognostic significance of unrecognized myocardial scar by CMR in patients without a history of MI is unknown. Methods and Results— One hundred ninety-five patients without a known prior MI underwent CMR for assessment of left ventricular (LV) function and late gadolinium enhancement (LGE). We assessed the prognostic value of LGE and other CMR variables beyond the strongest clinical predictors and built the best overall models for major adverse cardiac events (MACE) and cardiac mortality. During a median follow-up of 16 months, 31 patients (18%) experienced MACE, including 17 deaths. LGE demonstrated the strongest unadjusted associations with MACE and cardiac mortality (hazard ratios of 8.29 and 10.9, respectively; both P<0.0001). Patients in the lowest tertile of LGE-involved myocardium (mean LV mass, 1.4%) experienced a >7-fold increased risk for MACE. By multivariable analyses, LGE was independently associated with MACE beyond the clinical model (P<0.0001) or the clinical model combined with angiographically significant coronary stenosis (P=0.0007), LV ejection fraction (P=0.001), LV end-systolic volume index (P=0.0006), or segmental WMA (P=0.002). LGE remained the strongest predictor selected in the best overall models for MACE and cardiac mortality. Conclusions— Among patients with a clinical suspicion of coronary artery disease but without a history of MI, LGE involving a small amount of myocardium carries a high cardiac risk. In addition, LGE provides incremental prognostic value to MACE and cardiac mortality beyond common clinical, angiographic, and functional predictors.

Prognostic value of thallium-201 myocardial perfusion imaging. A diagnostic tool comes of age.

D uring the past 10 years, the use of thallium201 myocardial perfusion imaging has undergone considerable expansion and evaluation. Originally conceived as a noninvasive diagnostic tool useful in determining the presence or absence of anatomical coronary artery disease,1-4 201T1 imaging has now been shown to have important prognostic value in a wide spectrum of patients with coronary artery disease.5-49 This prognostic value derives from the ability of 201T1 imaging to identify the presence and extent of jeopardized viable myocardium. After a brief background discussion, data are reviewed that concern the prognostic value of 201T1 imaging in three primary populations-1) patients presenting with known or suspected coronary artery disease, 2) post-myocardial infarction patients, and 3) patients undergoing noncardiac surgery. Data comparing the prognostic value of 201T1 predictors to other patient variables, including clinical, electrocardiographic, and angiographic variables, are discussed. Finally, the physiological basis of these observations are examined.

Prognostic value of exercise thallium-201 imaging in patients presenting for evaluation of chest pain

Accurate prognostic information is important in determining optimal management of patients presenting for evaluation of chest pain. In this study, the ability of exercise thallium-201 myocardial imaging to predict future cardiac events (cardiovascular death or nonfatal myocardial infarction) was correlated with clinical, coronary and left ventricular angiographic and exercise electrocardiographic data in 139 consecutive, nonsurgically managed patients followed-up over a 3 to 5 year period (mean follow-up, 3.7 +/- 0.9), using a logistic regression analysis. Among patients without prior myocardial infarction (100 of 139), the number of myocardial segments with transient thallium-201 defects was the only statistically significant predictor of future cardiac events when all patient variables were evaluated. Among patients with myocardial infarction before evaluation (39 of 139), angiographic ejection fraction was the only significant predictor of future cardiac events when all variables were considered. This study suggests an approach to evaluate the risk of future cardiac events in patients with possible ischemic heart disease.

2009 ACCF/AHA Focused Update on Perioperative Beta Blockade Incorporated Into the ACC/AHA 2007 Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery

It is essential that the medical profession play a significant role in critically evaluating the use of diagnostic procedures and therapies as they are introduced and tested in the detection, management, or prevention of disease states. Rigorous and expert analysis of the available data documenting

American College of Cardiology/American Heart Association Clinical Competence statement on stress testing: a report of the American College of Cardiology/American Heart Association/American College of Physicians--American Society of Internal Medicine Task Force on Clinical Competence.

The granting of clinical staff privileges is one of the primary mechanisms used by institutions to uphold the quality of care. The Joint Commission on Accreditation of Healthcare Organizations requires that the granting of initial or continuing medical staff privileges be based on assessment of applicants against professional criteria specified in medical staff bylaws. Physicians and other healthcare providers are thus charged with identifying the criteria that constitute professional competence and with evaluating their peers accordingly. The process of evaluating clinical knowledge and competence is often constrained by the evaluator’s own knowledge and ability to elicit the appropriate information, a problem that is compounded by the growing number of highly specialized procedures for which privileges are requested. The American College of Cardiology (ACC)/American Heart Association (AHA)/American College of Physicians–American Society of Internal Medicine (ACP-ASIM) Task Force on Clinical Competence was formed in 1998 to develop recommendations to attain and maintain the cognitive and technical skills necessary for the competent performance of a specific cardiovascular service, procedure, or technology. These documents are evidence based, and where evidence is not available, expert opinion is called upon to formulate recommendations. Indications and contraindications for specific services or procedures are not included in the scope of these documents. Recommendations are intended to assist those who must judge the competence of cardiovascular healthcare providers entering practice for the first time and/or those who are in practice and undergo periodic review of their practice expertise. Because the assessment of competence is complex and multidimensional, isolated recommendations contained herein may not necessarily be sufficient or appropriate for judging overall competence. Board specialty certification is not a required part of these recommendations but is another measure of expertise. This statement is a revision and extension of the previous ACP/ACC/AHA Task Force Statement on Clinical Competence in Exercise Testing. …

Incidence and Prognostic Implication of Unrecognized Myocardial Scar Characterized by Cardiac Magnetic Resonance in Diabetic Patients Without Clinical Evidence of Myocardial Infarction

Background— Silent myocardial infarctions (MIs) are prevalent among diabetic patients and inflict significant morbidity and mortality. Although late gadolinium enhancement (LGE) imaging by cardiac magnetic resonance (CMR) can provide sensitive characterization of myocardial scar, its prognostic significance in diabetic patients without any clinical evidence of MI is unknown. Methods and Results— We performed clinically indicated CMR imaging in 187 diabetic patients who were grouped by the absence (study group, n=109) or presence (control group, n=78) of clinical evidence of MI (clinical history of MI or Q waves on ECG). CMR imaging and follow-up were successful in 107 study patients (98%) and 74 control patients (95%). Cox regression analyses were performed to associate LGE with major adverse cardiovascular events (MACE), including death, acute MI, new congestive heart failure or unstable angina, stroke, and significant ventricular arrhythmias. LGE by CMR was present in 30 of 107 study patients (28%). At a median follow-up of 17 months, 38 of 107 patients (36%) experienced MACE, which included 18 deaths. Presence of LGE was associated with a >3-fold hazards increase for MACE and for death (hazard ratio, 3.71 and 3.61; P<0.001 and P=0.007, respectively). Adjusted to a model that combines patient age, sex, ST or T changes on ECG, and left ventricular end-systolic volume index, LGE maintained a >4-fold hazards increase for MACE (adjusted hazard ratio, 4.13; 95% confidence interval, 1.74 to 9.79; P=0.001). In addition, LGE provided significant prognostic value with MACE and with death adjusted to a diabetic-specific risk model for 5-year events. The presence of LGE was the strongest multivariable predictor of MACE and death by stepwise selection in the study patients. Conclusions— CMR imaging can characterize occult myocardial scar consistent with MI in diabetic patients without clinical evidence of MI. This imaging finding demonstrates strong association with MACE and mortality hazards that is incremental to clinical, ECG, and left ventricular function combined.

ACC/AHA 2006 Guideline Update on Perioperative Cardiovascular Evaluation for Noncardiac Surgery: Focused Update on Perioperative Beta-Blocker Therapy. A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Update the 2002 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery).

Cardiovascular Evaluation for Noncardiac Surgery: Focused Update on Perioperative Beta-Blocker Therapy A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Update the 2002 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery) Developed in Collaboration With the American Society of Echocardiography, American Society of Nuclear Cardiology, Heart Rhythm Society, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society for Vascular Medicine and BiologyThe American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Practice Guidelines makes every effort to avoid any actual, potential, or perceived conflict of interest that might arise as a result of an industry relationship or personal interest of the writing committee. Specifically, all members of the writing committee, as well as peer reviewers of the document, were asked to provide disclosure statements of all such relationships that might be perceived as real or potential conflicts of interest. These statements are reviewed by the parent task force, reported orally to all members of the writing committee at each meeting, and updated and reviewed by the writing committee as changes occur. Please see Appendix 1 for author relationships with industry and Appendix 2 for peer reviewer relationships with industry. These guidelines attempt to define practices that meet the needs of most patients in most circumstances. These guideline recommendations reflect a consensus of expert opinion after a thorough review of the available, current scientific evidence and are intended to improve patient care. If these guidelines are used as the basis for regulatory/payer decisions, the ultimate goal is quality of care and serving the patients best interests. The ultimate judgment regarding care of a particular patient must be made by the healthcare provider and patient in light of all the circumstances presented by that patient.

Extent of jeopardized viable myocardium determined by myocardial perfusion imaging best predicts perioperative cardiac events in patients undergoing noncardiac surgery

OBJECTIVES This study was undertaken to test the hypothesis that the risk of perioperative cardiac events is not simply determined by the presence of myocardium at risk, but is directly related to the extent of myocardium at risk as reflected in thallium-201 myocardial imaging. BACKGROUND The risk of perioperative cardiac events in patients undergoing noncardiac surgery has been related to the presence of transient defects on dipyridamole thallium-201 myocardial imaging, reflecting jeopardized viable myocardium. METHODS The study cohort consisted of 231 consecutive patients who underwent noncardiac surgery and had a preoperative dipyridamole thallium-201 imaging study. Patients with vascular reconstruction or bypass constituted the largest surgical subgroup (n = 140). For thallium-201 imaging data, each of three planar projections was divided into three segments (total nine segments) and each segment was interpreted as normal or showing a transient or fixed defect. The ability of clinical and thallium-201 imaging data to predict perioperative cardiac events was compared with stepwise multivariate logistic regression analysis. RESULTS Perioperative cardiac events occurred in 19 patients, including 5 with cardiac death, 7 with nonfatal myocardial infarction and 7 with unstable angina. For cardiac death or nonfatal myocardial infarction, the only significant multivariate predictors were the number of myocardial segments with transient thallium-201 defects (p < 0.0005) and a history of diabetes mellitus (p < 0.05). For all cardiac events, the only significant multivariate predictors were the number of myocardial segments with transient defects (p < 0.0001), diabetes mellitus (p < 0.05) and calcium channel blocker use (p < 0.05). CONCLUSIONS The probability of important cardiac events in patients undergoing noncardiac surgery is best predicted by the extent of myocardium at risk as reflected on thallium-201 myocardial perfusion imaging. A history of diabetes mellitus also has a significant influence on perioperative risk.