Ravin Davidoff

ACC/AHA 2004 guideline update for coronary artery bypass graft surgery: summary article. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1999 Guidelines for Coronary Artery Bypass Graft Surgery).

The American College of Cardiology (ACC)/American Heart Association (AHA) Task Force on Practice Guidelines regularly reviews existing guidelines to determine when an update or full revision is needed. This process gives priority to areas where major changes in text, particularly recommendations, are mentioned on the basis of new understanding of evidence. Minor changes in verbiage and references are discouraged. The ACC/AHA Guidelines for Coronary Artery Bypass Graft Surgery published in 1999 have now been updated. The full-text guidelines incorporating the updated material are available on the Internet (www.acc.org or www.americanheart.org) in both a version that shows the changes from the 1999 guidelines in track changes mode, with strike-through indicating deleted text and underlining indicating new text, and a “clean” version that fully incorporates the changes. This article describes the major areas of change reflected in the update in a format that we hope can be read and understood as a stand-alone document. Please note we have changed the table of contents headings in the 1999 guidelines from roman numerals to unique identifying numbers. Interested readers are referred to the full-length Internet version to completely understand the context of these changes. Classification of Recommendations and Level of Evidence are expressed in the ACC/AHA format as follows: ### Classification of Recommendations ### Level of Evidence

ACC/AHA Guidelines for Coronary Artery Bypass Graft Surgery: Executive Summary and Recommendations A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the 1991 Guidelines for Coronary Artery Bypass Graft Surgery)

The American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Practice Guidelines was formed to make recommendations regarding the appropriate use of diagnostic tests and therapies for patients with known or suspected cardiovascular disease. Coronary artery bypass graft (CABG) surgery is among the most common operations performed in the world and accounts for more resources expended in cardiovascular medicine than any other single procedure. Since the original Guidelines were published in 1991, there has been considerable evolution in the surgical approach to coronary disease, and at the same time there have been advances in preventive, medical, and percutaneous catheter approaches to therapy. These revised guidelines are based on a computerized search of the English literature since 1989, a manual search of final articles, and expert opinion. As with other ACC/AHA guidelines, this document uses ACC/AHA classifications I, II, and III as summarized below: Class I: Conditions for which there is evidence and/or general agreement that a given procedure or treatment is useful and effective. Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness or efficacy of a procedure. Class IIa: Weight of evidence/opinion is in favor of usefulness/efficacy. Class IIb: Usefulness/efficacy is less well established by evidence/opinion. Class III: Conditions for which there is evidence and/or general agreement that the procedure/treatment is not useful/effective and in some cases may be harmful. ### A. Hospital Outcomes Seven core variables (priority of operation, age, prior heart surgery, sex, left ventricular [LV] ejection fraction [EF], percent stenosis of the left main coronary artery, and number of major coronary arteries with significant stenoses) are the most consistent predictors of mortality after coronary artery surgery. The greatest risk is correlated with the urgency of operation, advanced age, and 1 or more prior coronary bypass surgeries. Additional variables that are related …

Echocardiographic assessment of patients with infectious endocarditis: Prediction of risk for complications

To enhance the echocardiographic identification of high risk lesions in patients with infectious endocarditis, the medical records and two-dimensional echocardiograms of 204 patients with this condition were analyzed. The occurrence of specific clinical complications was recorded and vegetations were assessed with respect to predetermined morphologic characteristics. The overall complication rates were roughly equivalent for patients with mitral (53%), aortic (62%), tricuspid (77%) and prosthetic valve (61%) vegetations, as well as for those with nonspecific valvular changes but no discrete vegetations (57%), although the distribution of specific complications varied considerably among these groups. There were significantly fewer complications in patients without discernible valvular abnormalities (27%). In native left-sided valve endocarditis, vegetation size, extent, mobility and consistency were all found to be significant univariate predictors of complications. In multivariate analysis, vegetation size, extent and mobility emerged as optimal predictors and an echocardiographic score based on these factors predicted the occurrence of complications with 70% sensitivity and 92% specificity in mitral valve endocarditis and with 76% sensitivity and 62% specificity in aortic valve endocarditis.

Cardiogenic shock caused by right ventricular infarction: A report from the SHOCK registry

OBJECTIVES The purpose of this study was to determine the characteristics and outcomes of patients with acute myocardial infarction (MI) complicated by cardiogenic shock due to predominant right ventricular (RV) infarction. BACKGROUND Although RV infarction has been shown to have favorable long-term outcomes, the influence of RV infarction on mortality in cardiogenic shock is unknown. METHODS We evaluated 933 patients in cardiogenic shock due to predominant RV (n = 49) or left ventricular (LV) failure (n = 884) in the SHould we emergently revascularize Occluded coronaries for Cardiogenic shocK? (SHOCK) trial registry. RESULTS Patients with predominant RV shock were younger, with a lower prevalence of previous MI (25.5 vs. 40.1%, p = 0.047), anterior MI, and multivessel disease (34.8 vs. 77.8%, p < 0.001) and a shorter median time between the index MI and the diagnosis of shock (2.9 vs. 6.2 h, p = 0.003) in comparison to patients with LV shock. In-hospital mortality was 53.1% versus 60.8% (p = 0.296) for patients with predominant RV and LV shock, respectively, and the influence of revascularization on mortality was not different between groups. Multivariate analysis revealed that RV shock was not an independent predictor of lower in-hospital mortality (odds ratio 1.07, 95% confidence interval 0.54 to 2.13). CONCLUSIONS Despite the younger age, lower rate of anterior MI, and higher prevalence of single-vessel coronary disease of RV compared with LV shock patients, and their similar benefit from revascularization, mortality is unexpectedly high in patients with predominant RV shock and similar to patients with LV shock.

Progression of ventricular wall thickening after liver transplantation for familial amyloidosis.

BACKGROUND Familial amyloidosis (FAP) is characterized by the progression of neurologic and cardiac impairment ultimately leading to death within 7 to 15 years after the onset of the disease. Liver transplantation represents the only definitive therapy for this disease and has been performed since 1990. METHODS To determine the effect of liver transplantation on disease progression, electrocardiography and Doppler echocardiography were performed and blindly analyzed on 11 patients with FAP who were followed 0.8 to 8.6 years before liver transplantation and 0.8 to 4.1 years after liver transplantation. RESULTS; After liver transplantation, five patients showed progression of left ventricular wall thickening with increased left ventricular mass, and three of these five showed a reduction in electrocardiographic voltage despite abolition of the mutant protein from the serum. Of the five patients showing progressive wall thickening, four had the transthyretin variant Glu 42 Gly and one patient had the Ala 36 Pro variant; none of the remaining six patients, all of whom possessed the Val 30 Met variant, showed echocardiographic changes. Although 9 of the 11 patients have shown symptomatic improvement in neurologic symptoms, 1 patient has developed heart failure and a second patient has suffered a sudden cardiac death. CONCLUSIONS After liver transplantation, patients with FAP should have regular clinical evaluations including electrocardiographic and echocardiographic examinations to look for continued deterioration in heart structure or function.

Right ventricular dysfunction: An independent predictor of adverse outcome in patients with myocarditis

To assess the predictive value of right ventricular systolic function in patients with active myocarditis, the echocardiograms of 23 patients with biopsy-confirmed myocarditis were reviewed. Right ventricular systolic function was evaluated qualitatively and quantitatively by descent of the right ventricular base. Patients were divided into those with normal right ventricular function, in whom right ventricular descent was 1.9 +/- 0.1 cm, and those with abnormal right ventricular function, in whom right ventricular descent was 0.8 +/- 0.1 cm (p < 0.001). There were no differences between the two groups in age, duration of symptoms, baseline hemodynamics, or histologic assessment. Initial left ventricular ejection fraction was significantly lower in patients with depressed right ventricular function (27.5 +/- 4.9%) compared with that in patients with normal right ventricular function (47.5 +/- 6.3%) (p = 0.01). The likelihood of an adverse outcome, defined as death or need for cardiac transplantation, was greater in patients with abnormal right ventricular function (right ventricular descent < or = 1.7 cm) than in patients with normal right ventricular function (right ventricular descent > 1.7 cm) (p < 0.03). Multivariate analysis revealed that right ventricular dysfunction as quantified by right ventricular descent was the most powerful predictor of adverse outcome.

Quantification of jet flow by momentum analysis: An in vitro color doppler flow study

Previous investigations have shown that the size of a regurgitant jet as assessed by color Doppler flow mapping is independently affected by the flow rate and velocity (or driving pressure) of the jet. Fluid dynamics theory predicts that jet momentum (given by the orifice flow rate multiplied by velocity) should best predict the appearance of the jet in the receiving chamber and also that this momentum should remain constant throughout the jet. To test this hypothesis, we measured jet area versus driving pressure, flow rate, velocity, orifice area, and momentum and showed that momentum is the optimal jet parameter: jet area = 1.25 (momentum).28, r = 0.989, p less than 0.0001. However, the very curvilinear nature of this function indicated that chamber constraint strongly affected jet area, which limited the ability to predict jet momentum from observed jet area. To circumvent this limitation, we analyzed the velocities per se within the Doppler flow map. For jets formed by 1-81-mm Hg driving pressure through 0.005-0.5-cm2 orifices, the velocity distribution confirmed the fluid dynamic prediction: Gaussian (bell-shaped) profiles across the jet at each level with the centerline velocity decaying inversely with distance from the orifice. Furthermore, momentum was calculated directly from the flow maps, which was relatively constant within the jet and in good agreement with the known jet momentum at the orifice (r = 0.99). Finally, the measured momentum was divided by orifice velocity to yield an accurate estimate of the orifice flow rate (r = 0.99). Momentum was also divided by the square of velocity to yield effective orifice area (r = 0.84). We conclude that momentum is the single jet parameter that best predicts the color area displayed by Doppler flow mapping. Momentum can be measured directly from the velocities within the flow map, and when combined with orifice velocity, momentum provides an accurate estimate of flow rate and orifice area.

Right coronary artery stenosis : an independent predictor of atrial fibrillation after coronary artery bypass surgery

OBJECTIVES This study attempted to determine the importance of severe proximal right coronary artery disease as a predictor of atrial fibrillation in patients after coronary artery bypass surgery. BACKGROUND Studies in patients undergoing noncardiac surgery have suggested that ischemia in the right coronary artery distribution is associated with a high incidence of atrial fibrillation. However, the importance of right coronary artery disease as a predictor of atrial fibrillation after bypass surgery is unknown. METHODS The occurrence of sustained postoperative atrial fibrillation was studied prospectively in 168 consecutive patients undergoing coronary artery bypass grafting. Patients were followed up postoperatively until discharge. Severe right coronary artery stenosis was defined as > or = 70% lumen narrowing. RESULTS Of 104 patients with proximal or mid right coronary artery stenosis, 45 (43%) had atrial fibrillation postoperatively compared with 12 (19%) of the 64 patients without significant right coronary disease (p = 0.001). Univariate predictors of atrial fibrillation included right coronary artery stenosis (p = 0.001), advancing age (p = 0.0001) and lack of beta-adrenergic blocking agent therapy after bypass surgery (p = 0.0004). Multivariate adjusted risk of developing atrial fibrillation after bypass surgery increased with the presence of severe right coronary artery disease (odds ratio 3.69, 95% confidence interval [CI] 1.61 to 8.48), advancing age (odds ratio 2.24/10 years, CI 1.48 to 3.41) and male gender (odds ratio 2.36, CI 1.01 to 5.49). The use of beta-blockers postoperatively was associated with a protective effect (odds ratio 0.4, CI 0.17 to 0.80). CONCLUSIONS The presence of severe right coronary artery stenosis is an independent and powerful predictor of atrial fibrillation after coronary artery bypass surgery. In association with age, gender and postoperative beta-blocker therapy, these variables can be used to identify patients at increased risk for developing this arrhythmia.

Echocardiographic Predictors of Survival and Response to Early Revascularization in Cardiogenic Shock

Background—Although echocardiography is used in diagnosis and management of myocardial infarction, it has not been established whether specific features of cardiac structure or function early in the course of cardiogenic shock provide prognostic value. The purposes of this substudy of the SHould we emergently revascularize Occluded Coronaries for cardiogenic shocK (SHOCK) trial were to describe the echocardiographic features of cardiogenic shock, identify findings on early echocardiograms associated with outcome, examine the interaction of such features with treatment, and determine whether these features could provide insights into the survival benefit observed with early revascularization and guide selection of patients for this strategy. Methods and Results—One hundred seventy-five echocardiograms performed within 24 hours of randomization to the early revascularization (ERV) or initial medical stabilization (IMS) arms of the trial were submitted for quantitative assessment, and 169 were suitable for analysis. The 2 groups were similar in terms of clinical and early echocardiographic characteristics. Mean left ventricular ejection fraction (LVEF) was 31%, and moderate or greater mitral regurgitation (MR) was noted in 39.1%. On multivariate analysis, the only independent predictors of survival were MR severity and LVEF. A survival benefit for the ERV strategy was observed at all levels of LVEF and MR. Conclusions—A wide range of cardiac structural and functional abnormalities exists in patients presenting with acute cardiogenic shock. Both short- and long-term mortality appear to be associated with initial left ventricular systolic function and MR as assessed by echocardiography, and a benefit of ERV is noted regardless of baseline LVEF or MR.

Usefulness of pulsed tissue Doppler imaging for evaluating systolic and diastolic left ventricular function in patients with AL (primary) amyloidosis

To clarify whether pulsed tissue Doppler imaging at multiple left ventricular LV sites could help to explain the mechanism of congestive heart failure (CHF) in patients with primary amyloidosis, we examined 86 consecutive patients with primary amyloidosis confirmed by biopsy (group I, 31 patients without cardiac involvement; group II, 31 patients with evidence of heart involvement but no CHF; and group III, 24 patients with heart involvement, clinical CHF, and normal fractional shortening >28%). Peak early diastolic myocardial velocities in group II were significantly lower than those in group I, and the values in group III were also significantly lower than those in group II at most sites. In contrast to diastolic abnormalities, peak systolic wall motion velocities in group III were significantly lower than those in group II, but there were no significant differences between groups I and II. Thus, cardiac amyloidosis is characterized by an initial impairment in early cardiac relaxation, whereas CHF is associated with an impairment of peak systolic wall motion velocities, most prominently seen in the longitudinal axis. This systolic dysfunction can be detected by pulsed tissue Doppler imaging, even when ejection fraction is in the normal range.