Cardiac resynchronisation therapy in patients with end-stage heart failure--long-term follow-up

BACKGROUND: Cardiac resynchronisation therapy (CRT) has been shown to be effective in the treatment of patients with end-stage heart failure (HF). However, long-term results of CRT have not yet been validated. AIM: To assess the sustained benefit of CRT in patients with end-stage HF at long-term follow-up. In addition, predictors of response to CRT were analysed. METHODS: Twenty-eight patients with end-stage HF, NYHA class >or=III (>or=II in patients with indications for ICD and echocardiographic signs of ventricular mechanical systolic dyssynchrony), left ventricular ejection fraction <35%, QRS duration >120 ms and left bundle branch block morphology received a biventricular device (BiV). In 27 patients LV pacing was achieved via the coronary sinus tributaries and in 1 patient an endocardial LV lead was introduced transseptally. Ten patients received an ICD-CRT device. The control group consisted of 29 patients fulfilling the criteria for ICD-CRT implantation in whom the CRT system was not implanted for various reasons. At baseline, 3 months after implantation, and then every 6 months the following parameters were evaluated: NYHA class, quality of life (QoL) score, QRS duration on surface ECG, and 6-minute walking distance. The need for hospitalisation assessed one year before and one year after implantation was compared. Follow-up was obtained up to 2 years. RESULTS: The NYHA class and 6-minute walking test were significantly improved in the CRT group after 3 months and continued to improve gradually until 24 months of follow-up. The QoL improvement at 6 months was sustained over 2 years. Hospitalisation rate due to worsening of HF decreased. One-year and two-year survival were significantly better in the CRT group than in the control group (94 and 87 vs. 80 and 73% respectively). The only predictor of clinical improvement after CRT implantation was baseline NYHA class. CONCLUSION: Clinical improvements with CRT are progressive and sustained over 2 years of follow-up.     

Cardiac resynchronization therapy in patients with end-stage inotrope-dependent class IV heart failure

Although cardiac resynchronization therapy (CRT) is beneficial in patients with drug-refractory New York Heart Association (NYHA) class III/IV heart failure (HF) and left ventricular (LV) dyssynchrony, CRT efficacy is not well established in patients with more advanced HF on inotropic support. Ten patients (age 55 +/- 13 years) with inotrope-dependent class IV HF (nonischemic [n = 6] and ischemic [n = 4]) received a CRT implantable cardioverter-defibrillator device. QRS duration was 153 +/- 25 ms (left branch bundle block [n = 7], intraventricular conduction delay [n = 2], and QRS <120 ms [n = 1]). The indication for CRT was based on either electrocardiographic criteria (n = 9) or echocardiographic evidence of LV dyssynchrony (n = 1). Intravenous inotropic therapy consisted of dobutamine (n = 6; 4.3 +/- 1.9 microg/kg/min) or milrinone (n = 4; 0.54 +/- 0.19 microg/kg/min) as inpatient (n = 3) or outpatient (n = 7) therapy for 146 +/- 258 days before CRT. One patient required ventilatory support before and during device implantation. All patients were alive at follow-up 1,088 +/- 284 days after CRT. Three patients underwent successful orthotopic cardiac transplantation after 56, 257, and 910 days of CRT. HF improved in 9 patients to NYHA classes II (n = 5) and III (n = 4). Intravenous inotropic therapy was discontinued in 9 of 10 patients after 15 +/- 14 days of CRT. LV volumes decreased (end-diastolic from 226 +/- 78 to 212 +/- 83 ml; p = 0.08; end-systolic from 174 +/- 65 to 150 +/- 78 ml; p <0.01). LV ejection fraction increased (23.5 +/- 4.3% to 32.0 +/- 9.1%; p <0.05). No implantable cardioverter-defibrillator shocks were recorded, and antitachycardia therapy for ventricular tachyarrhythmias was delivered in 1 patient. In conclusion, patients with end-stage inotrope-dependent NYHA class IV HF and LV dyssynchrony may respond favorably to CRT with long-term clinical benefit and improved LV function.     

Long-term outcome in diabetic heart failure patients treated with cardiac resynchronization therapy

BACKGROUND: Diabetes mellitus is an independent risk factor for increased morbidity and mortality in heart failure (HF) patients. AIMS: To compare functional and structural improvement, as well as long-term outcome, between diabetic and non-diabetic HF patients treated with cardiac resynchronization therapy (CRT). METHODS: We compared response to CRT in 141 diabetic and 214 non-diabetic consecutive patients. Major events were; death from any cause, urgent heart transplantation and implantation of a left ventricular (LV) assist device. Frequencies of hospitalisation and defibrillator (CRT-D) discharges were also analyzed. RESULTS: CRT was able to significantly improve functional capacity, ventricular geometry and neurohumoral imbalance in both diabetic and non-diabetic patients over a median follow-up time of 34 months. Overall event-free survival was similar in diabetic and non-diabetic patients (HR 1.23, p=0.363), as was survival free from CRT-D interventions (HR 1.72; p=0.115) and hospitalisations (HR 1.12; p=0.500). On multivariable analysis, NYHA class IV (p=0.002), low LV ejection fraction (p=0.002), absence of beta-blocker therapy (p<0.001), impaired renal function (p=0.003), presence of an epicardial lead (p=0.025), but not diabetes (p=0.821) were associated with a poor outcome after CRT. CONCLUSIONS: Diabetic HF patients treated with CRT had a very favourable functional and survival outcome, which was comparable to non-diabetic patients.     

Usefulness of preimplantation B-type natriuretic peptide level for predicting response to cardiac resynchronization therapy

Nearly 1/3 of patients with heart failure (HF) fail to respond to cardiac resynchronization therapy (CRT). The purpose of this study was to evaluate the value of preimplantation brain natriuretic peptide (BNP) in predicting the clinical response to CRT. We retrospectively analyzed 164 patients who underwent CRT. Patients with New York Heart Association functional class III or IV HF symptoms despite maximal medical therapy, who were not on inotropic medications, had left ventricular ejection fraction < or =35%, and QRS duration >130 ms were included in the study. CRT response in patients who survived at 6-month follow-up was defined as no HF hospitalization and improvement of > or =1 grades in the New York Heart Association classification. BNP assays were performed before implantation and at 6-month follow-up. Patients had ischemic (47%) or nonischemic (53%) cardiopathy. Responders (n = 107) and nonresponders (n = 57) had similar baseline characteristics. Cardiac death and hospitalization for HF occurred in 5 (4.7%) and 18 (31.6%) patients, respectively. CRT responders compared with nonresponders exhibited higher preimplantation BNP levels (800 +/- 823 vs 335 +/- 348 pg/ml, p = 0.0002) and a significant reduction in the QRS duration after implantation (-6 +/- 34 vs +7 +/- 32 ms, p = 0.048). The preimplantation BNP was the only independent predictor of the CRT response (p = 0.001). A BNP value > or =447 pg/ml demonstrated a sensitivity of 62% and specificity of 79% in identifying CRT response. In a subgroup of 41 patients who underwent Doppler tissue imaging analysis, the preimplantation BNP was higher in patients presenting with intraventricular dyssynchrony (845 +/- 779 vs 248 +/- 290 pg/ml, p = 0.04). In conclusion, the preimplantation BNP value independently predicts CRT response and was superior to QRS duration reduction in identifying CRT responders.     

Ventricular asynchrony predicts a better outcome in patients with chronic heart failure receiving cardiac resynchronization therapy

OBJECTIVES: The aim of this study was to evaluate whether the clinical benefit of cardiac resynchronization therapy (CRT) can be prospectively predicted by means of the baseline evaluation of left ventricular asynchrony. BACKGROUND: The reverse remodeling associated with CRT is more evident in patients with severe heart failure (HF) and left bundle branch block (LBBB) who have left ventricular asynchrony. METHODS: Baseline left ventricular asynchrony was assessed in 60 patients with severe HF and LBBB by calculating the electrocardiographic duration of QRS and the echocardiographic septal-to-posterior wall motion delay (SPWMD). Left ventricular size and left ventricular ejection fraction (LVEF), mitral valve regurgitation, and functional capacity were also evaluated. The progression toward HF (defined as a worsening clinical condition leading to a sustained increase in conventional therapies, hospitalization, cardiac transplantation, and death) was assessed during follow-up, as were the changes in LVEF after six months. RESULTS: During the median follow-up of 14 months, 16 patients experienced HF progression. Univariate analysis showed that ischemic cardiomyopathy, changes in the QRS duration after implantation, and SPWMD significantly correlated with events. At multivariate analysis, a long SPWMD remained significantly associated with a reduced risk of HF progression (hazard ratio: 0.91; 95% confidence interval: 0.83 to 0.99; p <0.05). An improvement in LVEF was observed in 79% of the patients with a baseline SPWMD of > or =130 ms and in 9% of those with an SPWMD of <130 ms (p <0.0001). CONCLUSIONS: Baseline SPWMD is a strong predictor of long-term clinical improvement after CRT in patients with severe HF and LBBB.     

Cardiac resynchronization with sequential biventricular pacing for the treatment of moderate-to-severe heart failure.

OBJECTIVES: The InSync III study evaluated sequential cardiac resynchronization therapy (CRT) in patients with moderate-to-severe heart failure and prolonged QRS. BACKGROUND: Simultaneous CRT improves hemodynamic and clinical performance in patients with moderate-to-severe heart failure (HF) and a wide QRS. Recent evidence suggests that sequentially stimulating the ventricles might provide additional benefit. METHODS: This multicenter, prospective, nonrandomized, six-month trial enrolled a total of 422 patients to determine the effectiveness of sequential CRT in patients with New York Heart Association (NYHA) functional class III or IV HF and a prolonged QRS. The study evaluated: whether patients receiving sequential CRT for six months experienced improvement in 6-min hall walk (6MHW) distance, NYHA functional class, and quality of life (QoL) over control group patients from the reported Multicenter InSync Randomized Clinical Evaluation (MIRACLE) trial; whether sequential CRT increased stroke volume compared to simultaneous CRT; and whether an increase in stroke volume translated into greater clinical improvements compared to patients receiving simultaneous CRT. RESULTS: InSync III patients experienced greater improvement in 6MHW, NYHA functional class, and QoL at six months compared to control (all p < 0.0001). Optimization of the sequential pacing increased (median 7.3%) stroke volume in 77% of patients. No additional improvement in NYHA functional class or QoL was seen compared to the simultaneous CRT group; however, InSync III patients demonstrated greater exercise capacity. CONCLUSIONS: Sequential CRT provided most patients with a modest increase in stroke volume above that achieved during simultaneous CRT. Patients receiving sequential CRT had improved exercise capacity, but no change in functional status or QoL.     

Cardiac resynchronisation as a rescue therapy in patients with catecholamine-dependent overt heart failure: results from a short and mid-term study

BACKGROUND: Cardiac resynchronisation therapy (CRT) is a validated treatment for heart failure (HF) patients in NYHA class III-IV despite optimal medical therapy. We aimed to assess the beneficial effects of CRT in patients with catecholamine-dependent overt HF (CDOHF). METHODS: We studied 20 CDOHF patients who had undergone CRT implantation. Patients had a mean baseline QRS duration of 174+/-25 ms and/or echocardiographic asynchrony, and LVEF of 18+/-3%. Mean follow-up was 18+/-12 months. Dependence on catecholamine agents was defined as the inability to stop or reduce drug infusion without re-occurrence of hypotension, low urine output and hypoxaemia. RESULTS: After CRT implantation, catecholamine agents were mostly withdrawn within 2 days and blood pressure, urine output and BNP rapidly improved within 24 h. During follow-up, survival rates were 85% at 3 months, 80% at 6 months and 55% at 18 months. Among the 9 deaths, 5 were related to overt HF, 3 to sudden cardiac death and 1 to non-cardiac death. LVEF improved from 18+/-3% to 21+/-4% three months after CRT implantation. CONCLUSION: "Rescue" CRT implantation in CDOHF patients allowed a rapid and successful catecholamine weaning in all studied patients. Furthermore, this immediate beneficial effect is sustained for more than one year in surviving patients.     

Comparison of outcomes for patients with nonischemic cardiomyopathy taking intravenous inotropes versus those weaned from or never taking inotropes at cardiac resynchronization therapy

Mixed cohorts of patients with ischemic and nonischemic end-stage heart failure (HF) with a QRS duration of ≥120 ms and requiring intravenous inotropes do not appear to benefit from cardiac resynchronization therapy (CRT). However, CRT does provide greater benefit to patients with nonischemic cardiomyopathy and might, therefore, be able to reverse the HF syndrome in such patients who are inotrope dependent. To address this question, 226 patients with nonischemic cardiomyopathy who received a CRT-defibrillator and who had a left ventricular ejection fraction of ≤35% and QRS of ≥120 ms were followed up for the outcomes of death, transplantation, and ventricular assist device placement. Follow-up echocardiograms were performed in patients with ≥6 months of transplant- and ventricular assist device-free survival after CRT. The patients were divided into 3 groups: (1) never took inotropes (n = 180), (2) weaned from inotropes before CRT (n = 30), and (3) dependent on inotropes at CRT implantation (n = 16). At 47 ± 30 months of follow-up, the patients who had never taken inotropes had had the longest transplant- and ventricular assist device-free survival. The inotrope-dependent patients had the worst outcomes, and the patients weaned from inotropes experienced intermediate outcomes (p <0.0001). Reverse remodeling and left ventricular ejection fraction improvement followed a similar pattern. Among the patients weaned from and dependent on inotropes, a central venous pressure <10 mm Hg on right heart catheterization before CRT was predictive of greater left ventricular functional improvement, more profound reverse remodeling, and longer survival free of transplantation or ventricular assist device placement. In conclusion, inotrope therapy before CRT is an important marker of adverse outcomes after implantation in patients with nonischemic cardiomyopathy, with inotrope dependence denoting irreversible end-stage HF unresponsive to CRT.     

Left ventricular dyssynchrony predicts response and prognosis after cardiac resynchronization therapy

OBJECTIVES: This study was designed to predict the response and prognosis after cardiac resynchronization therapy (CRT) in patients with end-stage heart failure (HF). BACKGROUND: Cardiac resynchronization therapy improves HF symptoms, exercise capacity, and left ventricular (LV) function. Because not all patients respond, preimplantation identification of responders is needed. In the present study, response to CRT was predicted by the presence of LV dyssynchrony assessed by tissue Doppler imaging. Moreover, the prognostic value of LV dyssynchrony in patients undergoing CRT was assessed. METHODS: Eighty-five patients with end-stage HF, QRS duration >120 ms, and left bundle-branch block were evaluated by tissue Doppler imaging before CRT. At baseline and six months follow-up, New York Heart Association functional class, quality of life and 6-min walking distance, LV volumes, and LV ejection fraction were determined. Events (death, hospitalization for decompensated HF) were obtained during one-year follow-up. RESULTS: Responders (74%) and nonresponders (26%) had comparable baseline characteristics, except for a larger dyssynchrony in responders (87 +/- 49 ms vs. 35 +/- 20 ms, p < 0.01). Receiver-operator characteristic curve analysis demonstrated that an optimal cutoff value of 65 ms for LV dyssynchrony yielded a sensitivity and specificity of 80% to predict clinical improvement and of 92% to predict LV reverse remodeling. Patients with dyssynchrony >/=65 ms had an excellent prognosis (6% event rate) after CRT as compared with a 50% event rate in patients with dyssynchrony <65 ms (p < 0.001). CONCLUSIONS: Patients with LV dyssynchrony >/=65 ms respond to CRT and have an excellent prognosis after CRT.     

Totally epicardial cardiac resynchronization therapy system implantation in patients with heart failure undergoing CABG

BACKGROUND: Systolic dyssynchrony is present in a considerable number of patients with heart failure (HF) undergoing coronary artery bypass grafting (CABG). Surgical revascularization offers an optimal setting for totally epicardial cardiac resynchronization therapy (CRT) system implantation. AIM: To assess the efficacy of totally epicardial CRT implantation during CABG, in patients with HF. METHODS: Twenty three patients with HF and dyssynchrony underwent totally epicardial CRT system implantation during CABG. This randomised, single-blind, cross-over study compared clinical and echocardiographic parameters during two periods: 3 months of active CRT (CRT+) and 3 months of inactive CRT (CRT-) pacing. RESULTS: Twenty two patients underwent randomisation and completed both study periods. In the CRT+ group more patients improved by two NYHA classes (p=0.028), had a longer 6-minute walk test distance (p=0.047) and better quality of life (p=0.003) compared with the CRT- group. Echocardiography revealed an improved LV ejection fraction (p<0.001), smaller LV end-systolic volume (p=0.04), reduced mitral regurgitation (p=0.026) and improved LV synchrony in the CRT+ group compared with the CRT- group. CONCLUSION: CRT delivered by a totally epicardial system implanted during CABG is associated with additional improvement of clinical and echocardiographic parameters in patients with HF and systolic dyssynchrony.     

Myocardial gene expression in heart failure patients treated with cardiac resynchronization therapy responders versus nonresponders.

OBJECTIVES: We studied whether functional improvement after cardiac resynchronization therapy (CRT) is associated with reversal of the heart failure (HF) gene program. BACKGROUND: Cardiac resynchronization therapy improves exercise tolerance and survival in patients with advanced congestive HF and dyssynchrony. METHODS: Twenty-four patients referred for CRT underwent left ventricular (LV) endomyocardial biopsies immediately before CRT implantation (baseline). In addition, 17 of them underwent LV endomyocardial biopsy procurement 4 months later (follow-up). In 6 control patients with normal LV function, LV biopsies were obtained at the time of coronary artery bypass grafting. The LV messenger ribonucleic acid (mRNA) levels of contractile and calcium regulatory genes were measured by quantitative real time polymerase chain reaction and normalized for glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The HF patients showing an improvement in New York Heart Association (NYHA) functional class by >1 score and a relative increase in LV ejection fraction > or =25% at 4 months after CRT were considered as responders. RESULTS: The HF patients were characterized by lower LV mRNA levels of alpha-myosin heavy chain (alpha-MHC), beta-myosin heavy chain (beta-MHC), sarcoplasmic reticulum calcium ATPase 2alpha (SERCA), phospholamban (PLN), and higher brain natriuretic peptide (BNP) mRNA levels as compared with control subjects. Responders to CRT (n = 11) showed an increase in LVEF (p < 0.001), a decrease in left ventricular end-diastolic diameter (p = 0.003), and NYHA functional class (p = 0.002), and a reduction in N-terminal proBNP levels (p = 0.032) as compared with baseline. This was associated with an increase in mRNA levels of alpha-MHC (p = 0.035), SERCA (p = 0.032), a decrease in BNP mRNA levels (p = 0.002), and an increase in the ratio of alpha-/beta-MHC (p = 0.018) and SERCA/PLN (p = 0.012). No significant changes in molecular profile were observed in nonresponders. CONCLUSIONS: In HF patients with electromechanical cardiac dyssynchrony, functional improvement related to CRT is associated with favorable changes in established molecular markers of HF, including genes that regulate contractile function and pathologic hypertrophy.     

Left ventricular apical wall motion abnormality is associated with lack of response to cardiac resynchronization therapy in patients with ischemic cardiomyopathy.

BACKGROUND: Many patients with appropriate indications fail to respond to cardiac resynchronization therapy (CRT). OBJECTIVE: The purpose of our study was to determine the relationship between CRT response and preimplantation apical wall motion abnormality. METHODS: We analyzed data from 83 patients with ischemic cardiomyopathy who underwent CRT. All patients had New York Heart Association class III or IV symptoms despite maximal medical therapy, left ventricular ejection fraction (LVEF) < or =35%, and QRS duration > or =130 ms or <130 ms with left ventricular dyssynchrony. CRT responders at 6 months were defined as surviving patients with: (1) no hospitalization for heart failure, and (2) improvement of New York Heart Association classification. Patients underwent echocardiography before and 6 months after implantation to assess changes in regional wall motion and LVEF. RESULTS: At baseline, CRT responders (n = 39) and nonresponders (n = 44) had similar LVEF (22.9% +/- 6.9% vs 23.1% +/- 8.3%), QRS duration (159 +/- 43 ms vs 159 +/- 36 ms), and medical treatment. CRT nonresponders had a higher prevalence of preimplantation apical wall motion abnormality (68% vs 33%, P = .003). Patients with baseline apical wall motion abnormalities (n = 43) were less likely than others (n = 40) to show improvement in wall motion at 6 months (30% vs 81%, P < .001) or clinical response to CRT (31% vs 64%, P = .003). CONCLUSION: The presence of a preimplantation apical wall motion abnormality was associated with a lower rate of CRT response in patients with ischemic cardiomyopathy.     

Levosimendan Improves Renal Function in Patients with Acute Decompensated Heart Failure: Comparison with Dobutamine

Background Levosimendan is a relatively new cardiac inotropic agent with calcium sensitizing activity. This study was conducted to investigate the effects of levosimendan (L) and dobutamine (D) on renal function in patients hospitalized with decompensated heart failure (HF). Method The present study included 88 consecutive patients hospitalized with acutely decompensated HF (New York Heart Association (NYHA) Class 3–4) requiring inotropic therapy. Patients were randomized 2:1 to either L or D for intravenous inotropic support. Diuretic therapy was kept constant during infusions. Renal function values, including serum creatinine (CR), blood urea nitrogen, 24-h urinary output levels and calculated glomerular filtration rate (GFR) were measured just prior to and 24 h after the infusions in all patients, and 48 and 72 h after the infusions in every second patient in both groups. The pre and post-infusion values of renal function and left ventricular ejection fraction (LVEF) were evaluated. Results LVEF increased significantly in both groups. Those in L showed a significant improvement in calculated GFR after 24 h, whereas those in D showed no significant change (median in change in L:+15.3%, median change in D: −1.33%). Furthermore, in the L group a significant improvement was observed in calculated GFR after 72 h compared to baseline levels, whereas in D no significant change (median change in L:+45.45%, median change in D: +0.09%) was seen. Both agents improved 24-h urinary output. Conclusion Levosimendan seems to provide beneficial effects in terms of improvement in renal function compared to dobutamine in patients with heart failure who require inotropic therapy.     

Responders to cardiac resynchronization therapy with narrow or intermediate QRS complexes identified by simple echocardiographic indices of dyssynchrony: the DESIRE study

BACKGROUND: Cardiac resynchronization therapy (CRT) is recommended for patients with NYHA class III-IV refractory heart failure (HF), ejection fraction <35% and a QRS >120 ms. We attempted to identify responders to CRT from echocardiographic (echo) indices of mechanical dyssynchrony in patients with QRS<150 ms. METHODS AND RESULTS: The study enrolled 51 men and 9 women (mean age: 64.5 years) in NYHA class III (n=54) or IV (n=6) presenting with a mean ejection fraction: 25.7%, LV end-diastolic diameter: 69.1 mm, and QRS=121+/-19 ms. All patients were implanted with a CRT system and followed for 1 year. Implantation was preceded and followed by clinical, functional and Doppler (D)-echo evaluation. The primary combined endpoint included 1) death from any cause, 2) HF-related hospitalisations, and 3) NYHA class at 6 months. Before implant, 27 patients had > or =1 echo criterion of mechanical dyssynchrony (DES+ group) and 33 had no evidence of dyssynchrony (DES- group). At 12 months, 8 patients (4 per group) had died, 7 from HF. As regards the primary endpoint at 6 months, 33 patients (55%) had improved, 10 (16%) were unchanged, and 17 (29%) had deteriorated. Clinical improvement was observed in 19 of 27 DES+ (70%), versus 14 of 33 DES- (42%) patients (P<0.04). Baseline QRS duration did not predict response to CRT. CONCLUSIONS: In this population of HF patients with QRS<150 ms, the presence of mechanical dyssynchrony at baseline D-echo examination, but not the QRS width, predicted 6-month clinical response to CRT.     

Clinical impact of off-label cardiac resynchronization therapy in end-stage heart failure patients on continuous intravenous inotrope

Background:

Potential benefits of off‐label cardiac resynchronization therapy (CRT) in end‐stage heart failure (EHF) patients have not been fully investigated.

Hypothesis:

Some EHF patients who are dependent on intravenous inotropes can benefit from CRT.

Methods:

We retrospectively enrolled 14 EHF patients who were dependent on intravenous inotropes at the time of CRT implantation. Mean duration of inotropic support was 51 ± 47 days before CRT device implantation. To identify the efficacy of CRT, we assessed the successful withdrawal rate from inotropic support and survival estimates after device implantation. We also tried to identify possible predictors for withdrawal by comparing patient demographics between successful withdrawal (SW) and nonwithdrawal (NW) groups.

Results:

Successful withdrawal was achieved in 9 (64%) of 14 patients 46 ± 33 days after CRT device implantation. Event‐free survival was longer in the SW group than in the NW group (810 ± 169 days vs 114 ± 34 days; P = 0.007). In addition, patients in the SW group showed a higher previous surgery rate (89% vs 20%; P = 0.010) and a lower grade of mitral regurgitation (median, 0 vs 2; P = 0.010) than those in the NW group.

Conclusions:

Our retrospective data showed potential benefits of CRT among EHFpatients. Treatment of mitral regurgitation might be an essential qualification for managing EHF patients with CRT. © 2011 Wiley Periodicals, Inc. The authors have no funding, financial relationships, or conflicts of interest to disclose.     

Long-term follow-up of cardiac resynchronization therapy in patients with end-stage heart failure

Long-term follow-up of cardiac resynchronization therapy. INTRODUCTION: Cardiac resynchronization therapy (CRT) has been introduced to treat patients with end-stage heart failure, and results of this technique are promising. The aim of our study was to assess the sustained benefit of CRT in a large patient cohort with end-stage heart failure at long-term follow-up. In addition, the prognosis of responders and nonresponders was evaluated. METHODS AND RESULTS: 125 patients with end-stage heart failure, NYHA class III or IV, LVEF<35%, QRS duration>120 msec and left bundle branch block morphology received a biventricular device. At baseline and 6 months after implantation the following parameters were evaluated: NYHA class, Minnesota Quality of life score, QRS duration on surface ECG, 6-minute walking distance and LVEF. Follow-up was obtained up to 3 years. After 6 months, patients were divided in clinical responders and nonresponders according to improvement in NYHA class. All clinical parameters improved significantly at 6-month follow-up. Hospitalization for heart failure was 3.8+/-4.9 days/year before and 0.7+/-1.6 days/year after CRT. Survival at 1-, 2-, and 3-year follow-up was 93%, 88%, and 85%, respectively. Responders (78%) showed a significantly better survival than nonresponders at 2- and 3-year follow-up (96% and 93% for responders versus 81% and 73% for nonresponders, P<0.05). CONCLUSION: The improvement in functional status and symptoms after CRT is maintained at long-term follow-up (up to 3 years). The clinical improvement was associated with a significant reduction in hospitalization rate which was also maintained over the years. Preimplantation selection of responders may result in even better long-term survival.     

Cardiac resynchronization therapy in patients with narrow QRS

Conduction delay affecting 30-50% of patients with NYHA class III-IV heart failure (HF) mainly results from left bundle branch block and leads to deterioration of cardiac contractility through intra- and interventricular dyssynchrony. Cardiac resynchronization therapy (CRT) has class I recommendation for the treatment of patients with severe systolic HF who have left ventricular ejection fraction less or equal to 35%, QRS duration greater than or equal to 120 ms. Nevertheless some studies have shown that systolic asynchrony is present in 27-43% of HF patients with narrow QRS complexes (defined as <120 ms). We present here results of CRT in 20 patients (13 male, 7 female). Main indication for CRT was ventricular dyssynchrony during basic cardiac rhythm or cardiac pacing independently of QRS width. In 4 patients width of QRS complex was less than 120 ms, in 3 QRS varied from 120 to 149 ms pts and in 13 it was equal to or exceeded 150 ms. CRT in patients with narrow QRS resulted in clinical improvement associated with increase of cardiac contractility and decrease of left ventricular end systolic volume. This allows to conclude that CRT can be beneficial for HF patients with narrow QRS and ventricular dyssynchrony.     

Usefulness of QRS duration to predict response to cardiac resynchronization therapy in patients with end-stage heart failure

Despite current selection criteria, 20% to 30% of patients treated with cardiac resynchronization therapy (CRT) do not benefit. It has been suggested that QRS duration may not be the optimal criterion to select patients for CRT. The objective of this study was to systematically evaluate the predictive value of QRS duration for response to CRT in a large group of consecutive patients. A total of 242 patients with heart failure scheduled for implantation of a CRT device were studied. Selection criteria for CRT included moderate to severe heart failure (New York Heart Association classes III to IV), left ventricular ejection fraction (LVEF)120 ms. Before CRT implantation, QRS duration and clinical status were assessed, and 2-dimensional echocardiography (LV volumes and LVEF) was performed. Clinical status and changes in LVEF and LV volumes were reassessed at 6-month follow-up. After 6 months of CRT, 68% of patients were classified as clinical responders (improvement of >or=1 grade in New York Heart Association class) and 60% as echocardiographic responders (decrease>10% in LV end-systolic volume). At baseline, no significant differences were observed in QRS duration between clinical responders and nonresponders and between echocardiographic responders and nonresponders. No significant relation was demonstrated between baseline QRS duration and improvement in clinical and echocardiographic variables at 6-month follow-up. In conclusion, baseline QRS duration is not predictive for clinical and echocardiographic responses to CRT at 6-month follow-up. Better predictors for CRT response are needed.     

Cardiac resynchronization therapy and valvular cardiomyopathy after corrective surgery

Cardiac resynchronization therapy (CRT) has been shown to have clinical benefits in certain groups of patients with advanced heart failure (HF). However, patients with valvular cardiomyopathy are underrepresented in randomized clinical studies. The aim of this study was to assess the medium-term (i.e., at 6 months) effects of CRT in patients with HF exclusively due to valvular disease. The study included 40 consecutive patients who underwent CRT device implantation. At 6 months, there were improvements in functional class, left ventricular remodeling, and intraventricular dyssynchrony parameters in treated patients. In this particular subgroup of patients, the benefits of CRT were similar to those observed in patients with HF due to other etiologies.     

Prognostic significance of beta-blocker up-titration in conjunction with cardiac resynchronization therapy in heart failure management

Clinical practice guidelines emphasize that optimal pharmacotherapy, including beta-blockers (BB), is a prerequisite before receiving cardiac resynchronization therapy (CRT) in eligible patients with heart failure (HF). However, the optimal dose of BB before CRT implantation cannot be tolerated in a number of patients. Sixty-three consecutive patients who underwent CRT in 2006–2013 were retrospectively investigated. Before receiving CRT, BB could not be introduced in 20 patients (32 %); the daily carvedilol-equivalent dose in other 43 patients was 5.6 ± 7.0 mg because of significant HF and bradycardia. After receiving CRT, BB could be introduced in almost all patients (n = 61, 97 %), and the daily BB dose increased from 5.6 ± 7.0 to 13.2 ± 7.8 mg (P < 0.001). Multivariate analysis indicated that the change of BB dose after CRT was independently associated with improved left ventricular end-systolic volume (LVESV) [β = ?0.36; 95 % confidence interval (CI) ?2.13 to ?0.45; P < 0.01] after 6-months follow-up. Furthermore, Cox proportional hazard analysis also showed that the change in the BB dose (hazard ratio, 0.92; 95 % CI, 0.87–0.98; P < 0.01) as well as the New York Heart Association functional classification was an independent predictor of cardiac events. After initiating CRT, BB therapy can be introduced and up-titrated in intolerant HF patients. The up-titrated dose of BB after CRT was an independent predictor for the improvement of LVESV and HF prognosis.