Clinical benefit of cardiac resynchronization therapy with a defibrillator in patients with an ejection fraction > 35% estimated by cardiac magnetic resonance.

INTRODUCTION AND OBJECTIVES: Cardiac resynchronization therapy with a defibrillator prolongs survival and improves quality of life in advanced heart failure. Traditionally, patients with ejection fraction > 35 estimated by echocardiography have been excluded. We assessed the prognostic impact of this therapy in a group of patients with severely depressed systolic function as assessed by echocardiography but with an ejection fraction > 35% as assessed by cardiac magnetic resonance. METHODS: We analyzed consecutive patients admitted for decompensated heart failure between 2004 and 2011. The patients were in functional class II-IV, with a QRS ≥ to 120 ms, ejection fraction ≤ 35% estimated by echocardiography, and a cardiac magnetic resonance study. We included all patients (n=103) who underwent device implantation for primary prevention. Ventricular arrhythmia, all-cause mortality and readmission for heart failure were considered major cardiac events. The patients were divided into 2 groups according to systolic function assessed by magnetic resonance. RESULTS: The 2 groups showed similar improvements in functional class and ejection fraction at 6 months. We found a nonsignificant trend toward a higher risk of all-cause mortality in patients with systolic function ≤ 35% at long-term follow-up. The presence of a pattern of necrosis identified patients with a worse prognosis for ventricular arrhythmias and mortality in both groups. CONCLUSIONS: We conclude that cardiac resynchronization therapy with a defibrillator leads to a similar clinical benefit in patients with an ejection fraction ≤ 35% or > 35% estimated by cardiac magnetic resonance. Analysis of the pattern of late gadolinium enhancement provides additional information on arrhythmic risk and long-term prognosis.

Etiological diagnosis of left ventricular dysfunction: computed tomography compared with coronary angiography and cardiac magnetic resonance.

INTRODUCTION AND OBJECTIVES: To evaluate the capability of multidetector computed tomography to diagnose the coronary etiology of left ventricular dysfunction compared with using invasive coronary angiography and magnetic resonance. METHODS: Forty consecutive patients with left ventricular dysfunction of uncertain etiology underwent invasive coronary angiography and contrast magnetic resonance. All patients were evaluated with multidetector computed tomography including coronary calcium presence and score, noninvasive coronary angiography, and myocardial tissue assessment. RESULTS: The sensitivity and specificity of the presence of coronary calcium to identify left ventricular dysfunction was 100% and 31%, respectively. If an Agatston calcium score of >100 is taken, specificity increases to 58% with sensitivity still 100%. Sensitivity and specificity for coronary angiography by multidetector computed tomography was 100% and 96%, respectively; for identifying necrosis in contrast acquisition it was 57% and 100%, respectively; and in late acquisition, 84% and 96%, respectively. To identify coronary ventricular dysfunction with necrosis, the sensitivity and specificity was 92% and 100%, respectively. CONCLUSIONS: Of all the diagnostic tools available in multidetector computed tomography, coronary angiography is the most accurate in determining the coronary origin of left ventricular dysfunction. A combination of coronary angiography and myocardial tissue study after contrast allows a single test to obtain similar information compared with the combination of invasive coronary angiography and contrast magnetic resonance.