Effects of sacubitril/valsartan on the functional capacity of real-world patients in Italy: the REAL.IT study on heart failure with reduced ejection fraction.

Background: Heart failure (HF) significantly affects the morbidity, mortality, and quality of life of patients. New therapeutic strategies aim to improve the functional capacity and quality of life of patients while controlling HF-related risks. Real-world data on both the functional and cardiopulmonary exercise capacities of patients with HF with reduced ejection fraction upon sacubitril/valsartan use are lacking. Methods: A multicenter, retrospective, cohort study, called REAL.IT, was performed based on the data collected from the electronic medical records of nine specialized HF centers in Italy. Cardiopulmonary exercise testing was performed at baseline and after 12 months of sacubitril/valsartan therapy, monitoring carbon dioxide production (VCO2) and oxygen consumption (VO2). Results: The functional capacities of 170 patients were evaluated. The most common comorbidities were hypertension and diabetes (i.e., 53.5 and 32.4%, respectively). At follow-up, both the VO2 peak (from 15.1 ± 3.7 ml/kg/min at baseline to 17.6 ± 4.7 ml/kg/min at follow-up, p < 0.0001) and the predicted % VO2 peak (from 55.5 ± 14.1 to 65.5 ± 16.9, p < 0.0001) significantly increased from baseline. The VO2 at the anaerobic threshold (AT-VO2) increased from 11.5 ± 2.6 to 12.5 ± 3.3 ml/kg/min (p = 0.021), and the rate ratio between the oxygen uptake and the change in work (ΔVO2/Δwork slope) improved from 9.1 ± 1.5 to 9.9 ± 1.6 ml/min/W (p < 0.0001). Conclusions: Sacubitril/valsartan improves the cardiopulmonary capacity of patients with HFrEF in daily clinical practice in Italy.

The additive prognostic value of end-systolic pressure-volume relation by stress CMR in patients with known or suspected coronary artery disease.

PURPOSE: The difference between rest and peak stress end-systolic pressure-volume relation (ΔESPVR) is an afterload-independent index of left ventricular (LV) contractility. We assessed the independent prognostic value of ΔESPVR index by dipyridamole stress-cardiovascular magnetic resonance (CMR) in patients with known/suspected coronary artery disease (CAD). METHODS: We considered 196 consecutive patients (62.74 ± 10.66 years, 49 females). Wall motion and perfusion abnormalities at rest and peak stress were analysed. Replacement myocardial fibrosis was detected by late gadolinium enhancement (LGE) technique. The ESPVR was evaluated at rest and peak stress from raw measurement of systolic arterial pressure and end-systolic volume by biplane Simpson's method. RESULTS: A reduced ΔESPVR index (≤ 0.02 mmHg/mL/m2) was found in 88 (44.9%) patients and it was associated with a lower LV ejection fraction (EF) and with a higher frequency of abnormal stress CMR and myocardial fibrosis. During a mean follow-up of 53.17 ± 28.21 months, 50 (25.5%) cardiac events were recorded: 5 cardiac deaths, 17 revascularizations, one myocardial infarction, 23 hospitalisations for heart failure or unstable angina, and 4 ventricular arrhythmias. According to Cox regression analysis, diabetes, family history, LVEF, abnormal stress CMR, myocardial fibrosis, and reduced ΔESPVR were significant univariate prognosticators. In the multivariate analysis the independent predictors were ΔESPVR index ≤ 0.02 mmHg/mL/m2 (hazard ratio-HR = 2.58, P = 0.007), myocardial fibrosis (HR = 2.13, P = 0.036), and diabetes (HR = 2.33, P = 0.012). CONCLUSION: ΔESPVR index by stress-CMR was independently associated with cardiac outcomes in patients with known/suspected CAD, in addition to replacement myocardial fibrosis and diabetes. Thus, the assessment of ΔESPVR index may be included into the standard stress-CMR exam to further stratify the patients.

Effects of Sacubitril/Valsartan on Exercise Capacity in Patients with Heart Failure with Reduced Ejection Fraction and the Role of Percentage of Delayed Enhancement Measured by Cardiac Magnetic Resonance in Predicting Therapeutic Response: A Multicentre Study.

Background: This study aims to evaluate the cardiopulmonary effects of sacubitril/valsartan therapy in patients with heart failure with reduced ejection fraction (HFrEF), investigating a possible correlation with the degree of myocardial fibrosis, as assessed by cardiac magnetic resonance. Methods: A total of 134 outpatients with HFrEF were enrolled. Results: After a mean follow-up of 13.3 ± 6.6 months, an improvement in ejection fraction and a reduction in E/A ratio, inferior vena cava size and N-terminal pro-B-type natriuretic peptide levels were observed. At follow-up, we observed an increase in VO2 peak of 16% (p<0.0001) and in O2 pulse of 13% (p=0.0002) as well as an improvement in ventilatory response associated with a 7% reduction in the VE/VCO2 slope (p=0.0001). An 8% increase in the ΔVO2/Δ work ratio and an 18% increase in exercise tolerance were also observed. Multivariate logistic regression analysis showed that the main predictors of events during follow-up were VE/VCO2 slope >34 (OR 3.98; 95% CI [1.59-10.54]; p=0.0028); ventilatory oscillatory pattern (OR 4.65; 95% CI [1.55-16.13]; p=0.0052); and haemoglobin level (OR 0.35; 95% CI [0.21-0.55]; p<0.0001). In patients who had cardiac magnetic resonance, when delayed enhancement >4.6% was detected, a lower response after sacubitril/valsartan therapy was observed as expressed by improvement in ΔVO2 peak, O2 pulse, LVEF and N-terminal pro-B-type natriuretic peptide. No significant differences were observed in ΔVO2/Δ work and VE/VCO2 slope. Conclusion:Sacubitril/valsartan improves cardiopulmonary functional capacity in HFrEF patients. The presence of myocardial fibrosis on cardiac magnetic resonance is a predictor of response to therapy.

Pressure-volume relationship by pharmacological stress cardiovascular magnetic resonance.

The variation between rest and peak stress end-systolic pressure-volume relation (ΔESPVR) is an index of myocardial contractility, easily obtained during routine stress echocardiography and never tested during dipyridamole stress-cardiac magnetic resonance (CMR). We assessed the ΔESPVR index in patients with known/suspected coronary artery disease (CAD) who underwent dipyridamole stress-CMR. One-hundred consecutive patients (24 females, 63.76 ± 10.17 years) were considered. ESPVR index was evaluated at rest and stress from raw measurement of systolic arterial pressure and end-systolic volume by biplane Simpson's method. The ΔESPVR index showed a good inter-operator reproducibility. Mean ΔESPVR index was 0.48 ± 1.45 mmHg/mL/m2. ΔESPVR index was significantly lower in males than in females. ΔESPVR index was not correlated to rest left ventricular end-diastolic volume index or ejection fraction. Forty-six of 85 patients had myocardial fibrosis detected by the late gadolinium enhancement technique and they showed significantly lower ΔESPVR values. An abnormal stress CMR was found in 25 patients and they showed significantly lower ΔESPVR values. During a mean follow-up of 56.34 ± 30.04 months, 24 cardiovascular events occurred. At receiver-operating characteristic curve analysis, a ΔESPVR < 0.02 mmHg/mL/m2 predicted the presence of future cardiac events with a sensitivity of 0.79 and a specificity of 0.68. The noninvasive assessment of the ΔESPVR index during a dipyridamole stress-CMR exam is feasible and reproducible. The ΔESPVR index was independent from rest LV dimensions and function and can be used for a comparative assessment of patients with different diseases. ΔESPVR index by CMR can be a useful and simple marker for additional prognostic stratification.

Frailty in Acute and Chronic Coronary Syndrome Patients Entering Cardiac Rehabilitation.

Worldwide population ageing is partly due to advanced standard of care, leading to increased incidence and prevalence of geriatric syndromes such as frailty and disability. Hence, the age at the onset of acute coronary syndromes (ACS) keeps growing as well. Moreover, ageing is a risk factor for both frailty and cardiovascular disease (CVD). Frailty and CVD in the elderly share pathophysiological mechanisms and associated conditions, such as malnutrition, sarcopenia, anemia, polypharmacy and both increased bleeding/thrombotic risk, leading to a negative impact on outcomes. In geriatric populations ACS is associated with an increased frailty degree that has a negative effect on re-hospitalization and mortality outcomes. Frail elderly patients are increasingly referred to cardiac rehabilitation (CR) programs after ACS; however, plans of care must be tailored on individual's clinical complexity in terms of functional capacity, nutritional status and comorbidities, cognitive status, socio-economic support. Completing rehabilitative intervention with a reduced frailty degree, disability prevention, improvement in functional state and quality of life and reduction of re-hospitalization are the goals of CR program. Tools for detecting frailty and guidelines for management of frail elderly patients post-ACS are still debated. This review focused on the need of an early identification of frail patients in elderly with ACS and at elaborating personalized plans of care and secondary prevention in CR setting.

A case of extensive biatrial clot straddling the patent foramen ovale.

Patent foramen ovale (PFO) is a common abnormality that occurs in about 25% of the adult population. In most cases is a benign finding, but sometimes the communication between the right and the left atria can be a conduit for thrombi.

Exercise for slowing the progression of atherosclerotic process: effects on inflammatory markers.

Atherosclerosis is a dynamic process driven by all cardiovascular risk factors that can be briefly divided into an early and a late phase. Inflammation is one of the fundamental substrates that initiates the atherosclerotic process in the early stages and promotes and maintains it in the final stages. In the last decades, clinical and experimental data have shown that inflammation is supported by mediators that respond to physical activity. The present review aimed at investigating the effect of physical exercise on inflammatory mediators, both the positive ones that have a proinflammatory effect (interleukin 6, c-reactive protein and tumor necrosis factor α, interferon γ, high-mobility group box-1), and the negative ones which have an anti-inflammatory effect (interleukin 10). Pooled data support the evidence that physical exercise can directly modulate the activity of inflammatory cytokines slowing down or preventing the formation of the atherosclerotic stage.

Mutual relationship between heart failure and atrial fibrillation.

Atrial fibrillation (AF) and heart failure (HF) are evolving epidemies, together responsible for substantial human suffering and health-care expenditure. The simultaneous co-hexistence of the two conditions is associated with mortality rates higher than those observed in individuals with only one or none of them. Patients with concomitant HF and AF suffer from even worse symptoms and poorer prognosis, yet evidence-based evaluation and management of this group of patients is lacking. In this review, we evaluate the common mechanisms for the development of AF in HF patients and vice versa, focusing on the evidence for potential treatment strategies. Recent data have suggested that these patients may respond differently if compared to those with HF or AF alone. These results highlight the clear clinical need to identify and treat these diseases according to best evidence, in order to prevent adverse outcomes and reduce the huge burden that HF and AF are expected to have on global healthcare systems in the future.

Prevalence and prognostic impact of nonischemic late gadolinium enhancement in stress cardiac magnetic resonance.

AIM: To assess the prevalence and prognostic significance of NI-LGE in patients undergoing stress-CMR. METHODS: Stress-CMR with either dipyridamole or adenosine was performed in 283 patients (228 men, 81%) including perfusion imaging, wall motion evaluation and LGE. Follow-up was completed in all enrolled patients (median time: 1850 days; interquartile range: 1225-2705 days). Composite endpoint included cardiac death, ventricular tachycardia, myocardial infarction, stroke, hospitalization for cardiac cause and coronary revascularization performed beyond 90 days from stress-CMR scans. RESULTS: One hundred and twelve patients (40%) had negative LGE (no-LGE), 140 patients (49%) I-LGE and 31 patients (11%) NI-LGE. Twenty-five events occurred in the no-LGE group, 68 in I-LGE and 11 in the NI-LGE group. On survival curves, patients with NI-LGE had worse prognosis than patients with no-LGE regardless of the presence of inducible perfusion defects. No significant prognostic differences were found between I-LGE and NI-LGE. CONCLUSION: NI-LGE can be detected in 11% of patients during stress-CMR providing a diagnosis of nonischemic cardiac disease. Patients with NI-LGE have worse prognosis than those with no-LGE.

Reverse remodeling and arrhythmic burden reduction in a patient with an implantable cardioverter defibrillator treated with sacubitril/valsartan: Case report.

Sacubitril/valsartan has been shown to reduce cardiovascular mortality and hospitalizations in patients with HFrEF when compared to enalapril. There are also some evidences of its potential antiarrhythmic effects. We present a report where we found a relation between reverse ventricular remodeling and arrhythmic reduction in a patient treated with sacubitril/valsartan.

Early Detection of Myocardial Damage: A Multimodality Approach.

Cardiovascular diseases are possible complications of antineoplastic treatment and may lead to premature morbidity and mortality among cancer survivors. A symptom-based follow-up is ineffective, and there are growing evidences that early detection of myocardial damage in patients treated with antineoplastic drugs is the key point to prevent the occurrence of damage and improve the prognosis of these patients. Different techniques have been proposed to monitor cardiac function in oncologic patients such as cardiac imaging (echocardiography, nuclear imaging, and cardiac magnetic resonance) and biomarkers (troponin and natriuretic peptides). The European Association of Cardiovascular Imaging/American Society of Echocardiography consensus document encourages an integrated approach to early detect cardiotoxicity.

Sacubitril/Valsartan Improves Autonomic Function and Cardiopulmonary Parameters in Patients with Heart Failure with Reduced Ejection Fraction.

BACKGROUND: Heart rate recovery (HRR) is a marker of vagal tone, which is a powerful predictor of mortality in patients with cardiovascular disease. Sacubitril/valsartan (S/V) is a treatment for heart failure with reduced ejection fraction (HFrEF), which impressively impacts cardiovascular outcome. This study aims at evaluating the effects of S/V on HRR and its correlation with cardiopulmonary indexes in HFrEF patients. METHODS: Patients with HFrEF admitted to outpatients' services were screened out for study inclusion. S/V was administered according to guidelines. Up-titration was performed every 4 weeks when tolerated. All patients underwent laboratory measurements, Doppler-echocardiography, and cardiopulmonary exercise stress testing (CPET) at baseline and at 12-month follow-up. RESULTS: Study population consisted of 134 HFrEF patients (87% male, mean age 57.9 ± 9.6 years). At 12-month follow-up, significant improvement in left ventricular ejection fraction (from 28% ± 5.8% to 31.8% ± 7.3%, p < 0.0001), peak exercise oxygen consumption (VO2peak) (from 15.3 ± 3.7 to 17.8 ± 4.2 mL/kg/min, p < 0.0001), the slope of increase in ventilation over carbon dioxide output (VE/VCO2 slope )(from 33.4 ± 6.2 to 30.3 ± 6.5, p < 0.0001), and HRR (from 11.4 ± 9.5 to 17.4 ± 15.1 bpm, p = 0.004) was observed. Changes in HRR were significantly correlated to changes in VE/VCO2slope (r = -0.330; p = 0.003). After adjusting for potential confounding factors, multivariate analysis showed that changes in HRR were significantly associated to changes in VE/VCO2slope (Beta (B) = -0.975, standard error (SE) = 0.364, standardized Beta coefficient (Bstd) = -0.304, p = 0.009). S/V showed significant reduction in exercise oscillatory ventilation (EOV) detection at CPET (28 EOV detected at baseline CPET vs. 9 EOV detected at 12-month follow-up, p < 0.001). HRR at baseline CPET was a significant predictor of EOV at 12-month follow-up (B = -2.065, SE = 0.354, p < 0.001). CONCLUSIONS: In HFrEF patients, S/V therapy improves autonomic function, functional capacity, and ventilation. Whether these findings might translate into beneficial effects on prognosis and outcome remains to be elucidated.

Clinical Evidence for Q10 Coenzyme Supplementation in Heart Failure: From Energetics to Functional Improvement.

Oxidative stress and mitochondrial dysfunction are hallmarks of heart failure (HF). Coenzyme Q10 (CoQ10) is a vitamin-like organic compound widely expressed in humans as ubiquinol (reduced form) and ubiquinone (oxidized form). CoQ10 plays a key role in electron transport in oxidative phosphorylation of mitochondria. CoQ10 acts as a potent antioxidant, membrane stabilizer and cofactor in the production of adenosine triphosphate by oxidative phosphorylation, inhibiting the oxidation of proteins and DNA. Patients with HF showed CoQ10 deficiency; therefore, a number of clinical trials investigating the effects of CoQ10 supplementation in HF have been conducted. CoQ10 supplementation may confer potential prognostic advantages in HF patients with no adverse hemodynamic profile or safety issues. The latest evidence on the clinical effects of CoQ10 supplementation in HF was reviewed.

Effect of intravenous iron replacement therapy on exercise capacity in iron deficient anemic patients after cardiac surgery.

Iron deficiency (ID) is recognized as an important comorbidity in patients undergoing cardiac surgery; however, it still remains under-diagnosed and under-treated in clinical practice. This study aims at comparing efficacy and the effects on exercise capacity of intravenous ferric carboxymaltose (FCM) versus ferric gluconate (FG) in patients with ID anemia (IDA) resulting from cardiac surgery. We retrospectively analyzed data from our records of in-hospital patients with IDA after cardiac surgery undergoing cardiac rehabilitation. Group I was treated with FG, group II with FCM. Efficacy measures included changes (baseline vs discharge) in hemoglobin (Hb) and in distance traveled at six-minutes walking test (6MWT). Data from 74 in-patients (mean age 67.5±10.4 years, 43% women) were analyzed. At discharge, patients treated with FCM showed higher levels of Hb (11.1±1.2g/dl vs 10.2±1.1 g/dl; p=0.001), greater distance traveled at 6MWT (279.2±108.8 meters vs 236.3±72.7 meters; p=0.048), and lower in-hospital rehabilitation length of stay (20.3±7 vs 25.3±11.7 days; p=0.043) as compared to FG group. At multivariate analysis, the most powerful predictors of Hb increase >1 g/dl at discharge were transferrin levels (p=0.019) and treatment with FCM (p<0.001). FCM replacement therapy and iron serum levels were the most powerful predictors of 6MWT distance improvement (>100 meters) at discharge (p=0.13 and p=0.003, respectively). In patients with IDA following cardiac surgery, intravenous FCM is effective in restoring Hb levels and in improving exercise capacity after cardiac surgery.

Prognostic Role of Late Gadolinium Enhancement in Patients With Hypertrophic Cardiomyopathy and Low-to-Intermediate Sudden Cardiac Death Risk Score.

Sudden cardiac death (SCD) is the most life-threating complication of hypertrophic cardiomyopathy. Guidelines of the European Society of Cardiology (ESC) suggest the implantation of an implantable cardioverter defibrillator in primary prevention according to a 5-year risk SCD score ≥6%. The aim of the study is to evaluate the prognostic role of late gadolinium enhancement (LGE) in patients with a 5-year risk SCD score <6%. In this multicenter study, we performed cardiac magnetic resonance in 354 consecutive hypertrophic cardiomyopathy patients (257 males, range of age 54 ± 17) with a risk SCD score <6% (302 with <4% and 52 with ≥4 and <6% risk). Hard cardiac events, including SCD, resuscitated cardiac arrest, appropriate implantable cardioverter defibrillator interventions, sustained ventricular tachycardia, occurred in 22 patients. LGE was detected in a high proportion (92%) of patients with hard cardiac events (p = 0.002). At receiver-operating characteristic curve analysis, LGE extent ≥10% was the best threshold to predict major arrhythmic events (area under the curve: 0.74). Kaplan-Meier curves showed that patients with LGE ≥10% had a worse prognosis than those with lower extent (p < 0.0001). LGE extent was the best independent predictor of hard cardiac events (hazard ratio 1.05; 95% confidence interval [CI] 1.03 to 107; p < 0.0001). The estimates 5-year risk of hard cardiac event was 2.5% (95% CI 0.8 to 4.2) in patients with LGE extent <10% and 23.4% (95% CI 10.2 to 36.5) for those with LGE extent ≥10%. In conclusion, this study demonstrates as the extent of LGE ≥10% is able to recognize additional patients at increased risk for malignant arrhythmic episodes in a population with low-to-intermediate ESC SCD risk score.

Sex differences in anthracycline-induced cardiotoxicity: the benefits of estrogens.

Anthracyclines are the cornerstone for many oncologic treatments, but their cardiotoxicity has been recognized for several decades. Female subjects, especially before puberty and adolescence, or after menopause, seem to be more at increased risk, with the prognostic impact of this sex issue being less consistent compared to other cardiovascular risk factors. Several studies imply that sex differences could depend on the lack of the protective effect of sex hormones against the anthracycline-initiated damage in cardiac cells, or on differential mitochondria-related oxidative gene expression. This is also reflected by the results obtained with different diagnostic methods, such as cardiovascular biomarkers and imaging techniques (echocardiography, magnetic resonance, and nuclear medicine) in the diagnosis and monitoring of cardiotoxicity, confirming that sex differences exist. The same is true about protective strategies from anthracycline cardiotoxicity. Indeed, first studied to withstand oxidative damage in response to ischemia/reperfusion (I/R) injury, cardioprotection has different outcomes in men and women. A number of studies assessed the differences in I/R response between male and female hearts, with oxidative stress and apoptosis being shared mechanisms between the I/R and anthracyclines heart damage. Sex hormones can modulate these mechanisms, thus confirming their importance in the pathophysiology in cardioprotection not only from the ischemia/reperfusion damage, but also from anthracyclines, fueling further cardio-oncologic research on the topic.

[Surgical management of hypertrophic obstructive cardiomyopathy: the role of mitral valve]. / Trattamento chirurgico della cardiomiopatia ipertrofica ostruttiva: il ruolo della valvola mitrale.

Hypertrophic obstructive cardiomyopathy (HOCM) is the most frequently inherited cardiovascular disease (prevalence in the general population of 1/500) and is characterized by significant left ventricular hypertrophy, especially in the interventricular septum, combined with small-volume cardiac cavities. Transaortic surgical septal myectomy is the most commonly used technique to treat HOCM, and is associated with low operative morbidity and mortality and a reduction of the outflow gradients. The composite operative mortality of only 0.4% (17/3695 patients) from 5 major high-volume centers in North America highlights the role of dedicated HOCM units. The involvement of the mitral valve in the pathophysiology of HOCM has been addressed as systolic anterior motion (SAM)-related left ventricular outflow tract obstruction. Hypertrophic cardiomyopathy mitral malformations include leaflet elongation and a wide array of malformations of the papillary muscles and chordae that can be detected by transthoracic and transesophageal echocardiography and by cardiac magnetic resonance. Because they participate fundamentally in the predisposition to SAM, they have increasingly been repaired surgically.

Early Effects of Sacubitril/Valsartan on Exercise Tolerance in Patients with Heart Failure with Reduced Ejection Fraction.

BACKGROUND: Sacubitril/valsartan in heart failure (HF) with reduced ejection fraction (HFrEF) was shown to be superior to enalapril in reducing the risk of death and hospitalization for HF. Our aim was to evaluate the cardiopulmonary effects of sacubitril/valsartan in patients with HFrEF. METHODS: We conducted an observational study. Ninety-nine ambulatory patients with HFrEF underwent serial cardiopulmonary exercise tests (CPET) after initiation of sacubitril/valsartan in addition to recommended therapy. RESULTS: At baseline, 37% of patients had New York Heart Association (NYHA) class III. After a median follow-up of 6.2 months (range 3⁻14.9 months) systolic blood pressure decreased from 117 ± 14 to 101 ± 12 mmHg (p < 0.0001), left ventricular ejection fraction (LVEF) increased from 27 ± 6 to 29.7 ± 7% (p < 0.0001), peak oxygen consumption (VO2) improved from 14.6 ± 3.3 (% of predicted = 53.8 ± 14.1) to 17.2 ± 4.7 mL/kg/min (% of predicted = 64.7 ± 17.8) (p < 0.0001), minute ventilation/carbon dioxide production relationship (VE/VCO2 Slope) decreased from 34.1 ± 6.3 to 31.7 ± 6.1 (p = 0.006), VO2 at anaerobic threshold increased from 11.3 ± 2.6 to 12.6 ± 3.5 mL/kg/min (p = 0.007), oxygen pulse increased from 11.5 ± 3.0 to 13.4 ± 4.3 mL/kg/min (p < 0.0001), and ∆VO2/∆Work increased from 9.2 ± 1.5 to 10.1 ± 1.8 mL/min/watt (p = 0.0002). CONCLUSION: Sacubitril/valsartan improved exercise tolerance, LVEF, peak VO2, and ventilatory efficiency at 6.2 months follow-up. Further studies are necessary to better clarify underlying mechanisms of this functional improvement.

Magnitude of QRS duration reduction after biventricular pacing identifies responders to cardiac resynchronization therapy.

BACKGROUND: Several studies have investigated the association between native QRS duration (QRSd) or QRS narrowing and response to biventricular pacing. However, their results have been conflicting. The aim of our study was to determine the association between the relative change in QRS narrowing index (QI) and clinical outcome and prognosis in patients who undergo cardiac resynchronization therapy (CRT) implantation. METHODS AND RESULTS: We included 311 patients in whom a CRT device was implanted in accordance with current guidelines for CRT. On implantation, the native QRS, the QRSd and the QI during CRT were measured. After 6months, 220 (71%) patients showed a 10% reduction in LVESV. The median [25th-75th] QI was 14.3% [7.2-21.4] and was significantly related to reverse remodeling (r=+0.22; 95%CI: 0.11-0.32, p=0.0001). The cut-off value of QI that best predicted LV reverse remodeling after 6months of CRT was 12.5% (sensitivity=63.6%, specificity=57.1%, area under the curve=0.633, p=0.0002). The time to the event death or cardiovascular hospitalization was significantly longer among patients with QI>12.5% (log-rank test, p=0.0155), with a hazard ratio (HR) of 0.3 [95%CI: 0.11-0.78]. In the multivariate regression model adjusted for baseline parameters, a 10% increment in QI (HR=0.61[0.44-0.83], p=0.002) remained significantly associated with CRT response. CONCLUSIONS: Patients with a larger decrease in QRSd after CRT initiation showed greater echocardiographic reverse remodeling and better outcome from death or cardiovascular hospitalization. QI is an easy-to-measure variable that could be used to predict CRT response at the time of pacing site selection or pacing configuration programming.