Heart failure with preserved ejection fraction in outpatients with unexplained dyspnea: a pressure-volume loop analysis.

OBJECTIVES: The aim of the present study was to diagnose heart failure with preserved ejection fraction (HFPEF) in outpatients with unexplained chronic dyspnea and to elucidate its underlying mechanisms in this population using invasive pressure-volume loop analysis. BACKGROUND: The diagnosis of HFPEF in stable outpatients with unexplained dyspnea is difficult. METHODS: Thirty patients (age 67 +/- 8.6 years, 27% males) with preserved left ventricular (LV) ejection fraction (>50%) and unexplained chronic New York Heart Association functional class II to III dyspnea underwent heart catheterization. Patients with significant coronary artery stenosis (>50%) were excluded. Pressure-volume loops were assessed using a conductance catheter at rest, hand-grip exercise, leg lifting, and nitroprusside and dobutamine infusion. RESULTS: Twenty (66%) patients showed LV end-diastolic pressure >16 mm Hg (HFPEF), whereas the remaining 10 patients served as controls. Patients with HFPEF had significantly higher end-diastolic stiffness (0.205 +/- 0.074 vs. 0.102 +/- 0.017, p < 0.001) at rest, and their end-diastolic pressure-volume relationship showed a consistent upward and leftward shift during all hemodynamic interventions compared with controls. Regarding the underlying mechanism of HFPEF, 14 (70%) patients had markedly increased end-diastolic stiffness, which was considered a sufficient single pathology to induce increased LV end-diastolic pressure. Four (20%) patients showed a concomitant presence of moderately increased stiffness and severe LV dyssynchrony, and the remaining 2 (10%) patients, with normal stiffness, showed significant exercise-induced mitral regurgitation at hand-grip exercise. If the invasive pressure measurements were absent, only 5 (25%) of the outpatients with HFPEF fulfilled the European Society of Cardiology definition of HFPEF. CONCLUSIONS: A significant proportion of stable outpatients with unexplained chronic dyspnea may have HFPEF. In the patients whom we studied, increased LV stiffness, dyssynchrony, and dynamic mitral regurgitation were the major mechanisms underlying development of HFPEF.

Myocardial viability and cardiac dyssynchrony as strong predictors of perioperative mortality in high-risk patients with ischemic cardiomyopathy having coronary artery bypass surgery.

OBJECTIVE: Myocardial viability and left ventricular dyssynchrony are important predictors of long-term outcomes in patients with ischemic left ventricular dysfunction. The objective of this study was to test the hypothesis that assessment of myocardial viability and left ventricular dyssynchrony will predict perioperative mortality in high-risk patients with ischemic left ventricular dysfunction having coronary artery bypass surgery. METHODS: The study consisted of 79 consecutive patients with ischemic cardiomyopathy (age 65 +/- 9 years; 81% men; ejection fraction 30% +/- 6%) and logistic European system for cardiac operative risk evaluation > 10% having coronary artery bypass surgery. Myocardial viability was assessed by delayed contrast-enhanced magnetic resonance imaging. Left ventricular dyssynchrony was calculated using tissue Doppler from measurements of regional electromechanical coupling times in left ventricular basal segments before coronary artery bypass surgery. RESULTS: Twenty (25.3%) patients died within 30 days following coronary artery bypass surgery. Survivors (n = 59) showed a larger extent of viable myocardium (6.9 +/- 3.6 viable segments vs 3.4 +/- 3.3 viable segments, P < .001) and smaller left ventricular dyssynchrony (75 +/- 5 ms vs 179 +/- 83 ms, P < .001) than nonsurvivors. The presence of significant dyssynchrony (>or=105 ms) and absence of myocardial viability (<5 viable segments) independently predicted 30-day mortality with hazard ratio 3.26, 95% confidence interval 1.61 to 8.33 (P < .01) and hazard ratio 1.72, 95% confidence interval 1.59 to 1.89 (P < .01), respectively. All but 2 patients (94.1%) with viable myocardium and without left ventricular dyssynchrony survived coronary artery bypass surgery as compared with only 12 (52.2%) patients with nonviable myocardium and severe dyssynchrony (P < .001). CONCLUSIONS: In high-risk patients with ischemic left ventricular dysfunction having coronary artery bypass surgery, both myocardial viability and left ventricular dyssynchrony are important predictors of perioperative outcome. Assessment of myocardial viability and left ventricular dyssynchrony should be a routine part of the preoperative evaluation of these patients.

Severe left ventricular dyssynchrony is associated with poor prognosis in patients with moderate systolic heart failure undergoing coronary artery bypass grafting.

OBJECTIVES: The objective of the present study was to assess the relationship between the presence of left ventricular (LV) dyssynchrony and clinical outcome in patients with moderate systolic heart failure undergoing coronary artery bypass graft (CABG) surgery. BACKGROUND: The presence of LV dyssynchrony is associated with poor prognosis in patients with LV dysfunction. METHODS: The study consisted of 215 consecutive patients with ischemic cardiomyopathy and dyspnea (age 65 +/- 9 years, 81% male) undergoing CABG. Dyssynchrony was calculated by tissue Doppler imaging from regional time intervals in basal LV segments before and 1 month after CABG. Myocardial viability was assessed using single-photon emission computed tomography (SPECT) before CABG. RESULTS: Twenty-five patients (11.6%) died within 30 days (in-hospital mortality) of CABG. The presence of pre-CABG dyssynchrony > or =119 ms had the highest predictive accuracy for in-hospital mortality, with a sensitivity of 84% and a specificity of 71%. During the median follow-up period of 359 days (interquartile range 219 to 561), an additional 19 patients (10.3%) died and 34 patients (18.5%) were hospitalized for worsening heart failure. At Cox regression analysis, post-CABG dyssynchrony > or =72 ms and > or =5 viable segments were identified as independent predictors of clinical events, with a hazard ratio (HR) of 5.02, 95% confidence interval (CI) 2.57 to 10.02 (p < 0.001), and an HR of 0.63, 95% CI 0.55 to 0.75 (p < 0.001), respectively. Patients without post-CABG dyssynchrony and with viable myocardium had excellent prognosis compared with patients with severe post-CABG dyssynchrony and nonviable myocardium (event rate 3% vs. 64%; p < 0.001). CONCLUSIONS: The presence of severe LV dyssynchrony is associated with poor clinical outcomes despite revascularization. These results advocate a routine assessment of both LV dyssynchrony and viability to predict outcome in systolic heart failure patients undergoing CABG surgery.