Cardiac resynchronization therapy improves ejection fraction and cardiac remodelling regardless of patients' age

Long-term outcome of cardiac resynchronization therapy patients in the elderly

Heart failure (HF) is a leading cause of mortality and hospitalization in the elderly. However, data are scarce about their response to device treatment such as cardiac resynchronization therapy (CRT). We aimed to evaluate the age-related differences in the effectiveness of CRT, procedure-related complications, and long-term outcome. Between 2000 and 2020, 2656 patients undergoing CRT implantation were registered and analyzed retrospectively. Patients were divided into 3 groups according to their age: group I, < 65; group II, 65-75; and group III, > 75 years. The primary endpoint was the echocardiographic response defined as a relative increase > 15% in left ventricular ejection fraction (LVEF) within 6 months, and the secondary endpoint was the composite of all-cause mortality, heart transplantation, or left ventricular assist device implantation. Procedure-related complications were also assessed. After implantation, LVEF showed significant improvement both in the total cohort [28% (IQR 24/33) vs. 35% (IQR 28/40); p < 0.01)] and in each subgroup (27% vs. 34%; p < 0.01, 29% vs. 35%; p < 0.01, 30% vs. 35%; p < 0.01). Response rate was similar in the 3 groups (64% vs. 62% vs. 56%; p = 0.41). During the follow-up, 1574 (59%) patients died. Kaplan-Meier curves revealed a significantly lower survival rate in the older groups (log-rank p < 0.001). The cumulative complication rates were similar among the three age groups (27% vs. 28% vs. 24%; p = 0.15). Our results demonstrate that CRT is as effective and safe therapy in the elderly as for young ones. The present data suggest that patients with appropriate indications benefit from CRT in the long term, regardless of age.

Ejection Fraction Improvement Does Not Reflect Changes in Quality of Life Following Cardiac Resynchronization Therapy

OBJECTIVE

To determine if health-related quality of life (HRQoL) improvement after cardiac resynchronization therapy (CRT) correlates with improved left-ventricular ejection fraction (EF).

BACKGROUND

CRT was reported to improve EF and HRQoL in clinical trials of heart failure with reduced EF (HFrEF). It is unknown if improvements in HRQoL reflect EF response to CRT.

METHODS

We included HFrEF patients who underwent CRT and had both pre- and post-CRT HRQoL assessment. EF response was categorized as absent (0% change or decrease), modest (0%-19% increase), or significant ( > 20% increase). We examined the associations between EF response and generic (PROMIS) and HF-specific (KCCQ-12) HRQoL.

RESULTS

The group included 115 patients with mean age of 65 years and baseline EF of 31%; 39% were female (n = 45). Nineteen percent (n = 22) had significant, 57% (n = 66) modest, and 23% (n = 27) absent EF responses. AF burden across significant (8.9%), modest (4.8%), and absent EF responders (1.4%) was similar ( P = 0.20). Significant improvements in KCCQ-12 (43.4-57.5, P = 0.003), current health visual analog scale (49.1-55.9, P = 0.042), PROMIS fatigue (58.9-55.1, P = 0.026), and PROMIS satisfaction (42.7-46.4, P = 0.020) resulted following CRT across all groups. There was no association between significant EF improvement and HRQoL by KCCQ-12 (nonresponse, 44.4%; modest response, 33.3%; and significant response, 22.2%) at 1 year ( P = 0.52 across all groups).

CONCLUSION

CRT was associated with a modest to significant EF response in a majority of patients. However, EF response did not significantly correlate with generic or HF-specific HRQoL measures. Further investigations are warranted into determinants of improved HRQoL following CRT.

Reverse re-modelling chronic heart failure by reinstating heart rate variability

Heart rate variability (HRV) is a crucial indicator of cardiovascular health. Low HRV is correlated with disease severity and mortality in heart failure. Heart rate increases and decreases with each breath in normal physiology termed respiratory sinus arrhythmia (RSA). RSA is highly evolutionarily conserved, most prominent in the young and athletic and is lost in cardiovascular disease. Despite this, current pacemakers either pace the heart in a metronomic fashion or sense activity in the sinus node. If RSA has been lost in cardiovascular disease current pacemakers cannot restore it. We hypothesized that restoration of RSA in heart failure would improve cardiac function. Restoration of RSA in heart failure was assessed in an ovine model of heart failure with reduced ejection fraction. Conscious 24 h recordings were made from three groups, RSA paced (n = 6), monotonically paced (n = 6) and heart failure time control (n = 5). Real-time blood pressure, cardiac output, heart rate and diaphragmatic EMG were recorded in all animals. Respiratory modulated pacing was generated by a proprietary device (Ceryx Medical) to pace the heart with real-time respiratory modulation. RSA pacing substantially increased cardiac output by 1.4 L/min (20%) compared to contemporary (monotonic) pacing. This increase in cardiac output led to a significant decrease in apnoeas associated with heart failure, reversed cardiomyocyte hypertrophy, and restored the T-tubule structure that is essential for force generation. Re-instating RSA in heart failure improves cardiac function through mechanisms of reverse re-modelling; the improvement observed is far greater than that seen with current contemporary therapies. These findings support the concept of re-instating RSA as a regime for patients who require a pacemaker.

Comparative effectiveness of CRT in older patients with heart failure: Systematic review and meta-analysis

OBJECTIVE

To perform meta-analyses comparing safety and effectiveness of cardiac resynchronization therapy (CRT) in older versus younger patients with heart failure with reduced ejection fraction (HFrEF).

BACKGROUND

Pivotal CRT trials enrolled patients with HFrEF significantly younger than the typical contemporary patient with HFrEF. Thus, risks and benefits in this older population with HFrEF are largely unknown.

METHODS

PubMed, The Cochrane Library, Scopus, and Web of Science were queried for comparative effectiveness studies of CRT in older HFrEF patients. Title, abstract, and full text screening was performed to identify studies comparing at least one pre-specified endpoint between older and younger adult patients with at least 50 participants. Random effects meta-analysis in LVEF mean difference (older minus younger) and relative risk (RR) of death, improvement in New York Heart Association (NYHA) class, and complications are reported along with estimates of heterogeneity.

RESULTS

In 7 studies, there was similar LVEF improvement between groups [mean difference 1.14; 95% CI -0.04 - 2.32, p=0.06, I 2 =53%]. Older patients were equally likely as younger patients to see an improvement in NYHA class of at least 1 in 6 studies [RR 0.99; 95% CI, 0.93 - 1.06; p=0.76; I 2 =25%]. No significant differences in the incidence of hematoma, pneumothorax, lead dislodgment, cardiac perforation, or infection requiring explant was observed. RR of mortality in 11 studies demonstrated higher risk of all-cause mortality in older patients [RR 1.05; 95% CI, 1.03 - 1.08, p<0.01, I 2 =0%].

CONCLUSIONS

Compared with younger patients, older patients receiving CRT were equally likely to experience improvement in LVEF, LVEDD, and NYHA class. There was no difference in procedural complications. The higher rate of all-cause mortality in older patients likely reflects a greater underlying risk of death from competing causes.

Does the Age Affect the Outcomes of Cardiac Resynchronization Therapy in Elderly Patients?

Background: More and more heart failure (HF) patients aged ≥ 75 years undergo cardiac resynchronization therapy (CRT) device implantation, however the data regarding the outcomes and their predictors are scant. We investigated the mid- to long-term outcomes and their predictors in CRT patients aged ≥ 75 years. Methods: Patients in the Cardiac Resynchronization Therapy Modular (CRT MORE) Registry were divided into three age-groups: <65 (group A), 65–74 (group B) and ≥75 years (group C). Mortality, hospitalization, and composite event rate were evaluated at 1 year and during long-term follow-up. Results: Patients (n = 934) were distributed as follows: group A 242; group B 347; group C 345. On 12-month follow-up examination, 63% of patients ≥ 75 years displayed a positive clinical response. Mortality was significantly higher in patients ≥ 75 years than in the other two groups, although the rate of hospitalizations for HF worsening was similar to that of patients aged 65–74 (7 vs. 9.5%, respectively; p = 0.15). Independent predictors of death and of negative clinical response were age >80 years, chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD). Over long-term follow-up (1020 days (IQR 680-1362)) mortality was higher in patients ≥ 75 years than in the other two groups. Hospitalization and composite event rates were similar in patients ≥ 75 years and those aged 65–74 (9 vs. 11.8%; p = 0.26, and 26.7 vs. 20.5%; p = 0.06). Conclusion: Positive clinical response and hospitalization rates do not differ between CRT recipients ≥ 75 years and those aged 65–74. However, age > 80 years, COPD and CKD are predictors of worse outcomes.

Impact of age on mid-term clinical outcomes and left ventricular reverse remodeling after cardiac resynchronization therapy

INTRODUCTION

The number of heart failure (HF) patients has been rapidly increasing in Japan, and considering the most explosive aging occurring in Asia, the management of elderly HF patients and longer life expectancy are critical issues. The aim of the present study was to evaluate whether the mid-term prognosis after cardiac resynchronization therapy (CRT) implantation was influenced by age and to investigate, in detail, the difference in the change ratio of echocardiographic parameters according to the age group of interest.

METHODS AND RESULTS

This retrospective analysis included 173 patients who underwent CRT implantation in our hospital from February 2008 to March 2019. Eighty patients (46%) were classified into the elderly group (≥75 years) and the rest in the non-elderly group. The study population was also classified with propensity score matching. The mid-term prognosis including all-cause death and hospitalization for HF, and the ratio of CRT responders were compared between the 2 groups. CRT response was defined as left ventricular (LV) end-systolic volume reduction ≥15% at follow-up echocardiography within a year. During a median follow-up of 1057 [interquartile range: 412, 2107] days, adverse events were not significantly different between the 2 groups before and after matching (before matching; all-cause death: log-rank p = 0.323, hospitalization for HF: log-rank p = 0.376, after matching; all-cause death: log-rank p = 0.325, hospitalization for HF: log-rank p = 0.516). Moreover, the rate of CRT responders was not significantly different between the 2 groups before and after matching (before matching, p = 0.718; after matching, p = 0.666).

CONCLUSIONS

In elderly HF patients, CRT provided the same clinical benefits as in non-elderly HF patients, furthermore, there was a similar trend in LV reverse remodeling between the 2 groups. The present study demonstrated that the indication of CRT implantation should not be determined by age.

The interactions between respiratory and cardiovascular systems in systolic heart failure

Heart failure (HF) is a complex and multifaceted disease. The disease affects multiple organ systems, including the respiratory system. This review provides three unique examples illustrating how the cardiovascular and respiratory systems interrelate because of the pathology of HF. Specifically, these examples outline the impact of HF pathophysiology on 1) respiratory mechanics and the mechanical "cost" of breathing; 2) mechanical interactions of the heart and lungs; and on 3) abnormalities of pulmonary gas exchange during exercise, and how this may be applied to treatment. The goal of this review is to, therefore, raise the awareness that HF, though primarily a disease of the heart, is accompanied by marked pathology of the respiratory system.

Predictors of clinical outcomes after cardiac resynchronization therapy in patients ≥75 years of age: a retrospective cohort study

Background

Cardiac resynchronization therapy has been shown to benefit selected patients with heart failure and reduced ejection fraction. Older patients have been underrepresented in randomized trials. This study was conducted to determine whether predictive factors for cardiac resynchronization therapy outcomes differ in patients older and younger than 75 years of age.

Methods

Consecutive patients who received a cardiac resynchronization device cardiac resynchronization therapy between 2013 and 2016 in our center were retrospectively included in this cohort study. The primary endpoint was cardiac resynchronization therapy effectiveness, which was defined as survival for one year with both no heart failure hospitalization and improvement by one or more NYHA class. The secondary endpoints were mortality, complications, and device therapies.

Results

Among the 243 patients included, 102 were ≥ 75 years old. Cardiac resynchronization therapy effectiveness was observed in 70 patients (50%) < 75 years old and in 48 patients (47%) ≥75 years old (p = 0.69). NYHA class ≥III (OR = 6.02; CI95% [1.33–18.77], p = 0.002) was a predictive factor for cardiac resynchronization therapy effectiveness only in the ≥75-year-old group, while atrial fibrillation was independently negatively associated with the primary endpoint in the < 75-year-old group (OR = 0.28; CI95% [0.13–0.62], p = 0.001). The one-year mortality rate was 14%, with no difference between age groups. Rescue cardiac resynchronization therapy and atrial fibrillation were independent predictive factors for mortality in both age groups. Eighty-two complications occurred in 45 patients (19%), with no difference between groups. Defibrillator use and QRS duration were independent predictive factors for complications in both age groups. There was no difference between groups considering device therapies.

Conclusion

At one year, cardiac resynchronization therapy response is not compromised by patient age. In older patients, highly symptomatic individuals with NYHA class ≥III have better outcomes after cardiac resynchronization therapy.

Meta-Analysis Comparing Neurohumoral Antagonist Use in Patients ≥75 Years Versus <75 Years Receiving Cardiac Resynchronization Therapy

Neurohumoral antagonists are the foundation of heart failure therapy in patients with reduced left ventricular ejection fraction. Cardiac resynchronization therapy (CRT) has also been associated with improved outcomes in these patients. We aimed to evaluate the use of neurohumoral antagonists in patients ≥75 years compared with <75 years of age receiving CRT. We searched electronic databases, up to December 20, 2016 for all studies reporting medication use in patients ≥75 years and <75 years of age who received CRT. We used random-effects meta-analysis models to summarize the studies. We retained 12 studies (1 randomized trial and 11 observational studies) enrolling 5,728 ≥75 years old and 9,549 patients of <75 years old. There were lower use of angiotensin converting enzyme inhibitors or angiotensin receptor blockers in patients ≥75 years compared with patients <75 years (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.47 to 0.74, p < 0.0001). In addition, there were lower use of mineralocorticoid receptor antagonists in patients ≥75 years compared with patients <75 years (OR 0.48, 95% CI 0.40 to 0.57, p < 0.0001). The use of β blockers was nonsignificantly lower in patients ≥75 years compared with patients <75 years (OR 0.70, 95% CI 0.47 to 1.03, p = 0.07). In conclusion, neurohumoral antagonists appeared to be underused in patients ≥75 years compared with patients <75 years receiving CRT. Consideration should be given to increase neurohumoral antagonism in patients ≥75 years referred for CRT.

Longitudinal evaluation of ventricular ejection fraction and NT-proBNP across heart failure subgroups

OBJECTIVES

Left ventricular ejection fraction (EF) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) are important surrogate markers of cardiac function and wall stress. Randomized trials of heart failure (HF) have shown improvements in survival in patients with reduced EF (<40%, HFrEF) but not with preserved EF (≥50%, HFpEF) or mid-range EF (40-49%, HFmrEF). Limited information is available on the trajectory of EF in contemporary heart failure management programs (HFMPs).

DESIGN

201 HF patients consecutively enrolled 2010-2011 in the outpatient-based HFMP of Skåne University Hospital in Lund were included in the study. Probable etiology, EF, NT-proBNP and medications were assessed at baseline and 1 year after enrollment.

RESULTS

HFrEF was the most common heart failure subgroup (78.1% of patients) in this HFMP, followed by HFmrEF (14.9%) and HFpEF (7.0%). The most common etiology was ischemic heart disease (IHD, 40.8%). Complete recovery of EF (>50%) was rare (14.1% of patients with HFrEF and 26.7% with HFmrEF), some degree of improvement was observed in 57.7% and 46.7% of patients. LVEF improved on average 9.1% in patients with HFrEF (p < .001) and NT-proBNP decreased from 4,202 to 2,030 pg/ml (p < .001). A similar trend was noticed for the HFmrEF group but was not statistically significant. The improvement in LVEF was consistent across subgroups with HF attributable to IHD (6.2%), idiopathic dilated cardiomyopathy (7.1%) and tachycardia-induced HF (17.5%).

CONCLUSIONS

This study provides estimates of the improvement in LVEF and NT-proBNP that can be expected with contemporary management across subgroups of HF and different etiologies in a contemporary HFMP.

Current Therapeutic Options for Heart Failure in Elderly Patients

Heart failure (HF) is a major and growing public health problem with high morbidity and mortality (Ponikowski et al., 2016). It affects 1-2% of the general population in developed countries, and the average age at diagnosis is 76 years. Because of a better management of acute phase and comorbidities, HF incidence is increasing in elderly patients, with a prevalence rising to 10% among people aged 65 years or older (Mozaffarian et al., 2014). Therefore, a substantial number of elderly patients need to be treated. However, because of clinical trial exclusion criteria or coexisting comorbidities, currently recommended therapies are widely based on younger population with a much lower mean age. In this review, we will focus on available pharmacological, electrical, and mechanical therapies, underlining pros, cons, and practical considerations of their use in this specific patient population.

Complications and 1-year benefit of cardiac resynchronization therapy in patients over 75 years of age - Insights from the German Device Registry

OBJECTIVE

Evidence on cardiac resynchronization therapy (CRT) in older patients is scarce and conflicting. Nevertheless, CRT in the elderly is of major practical relevance as heart failure prevalence increases with age.

METHODS

The German Device Registry (DEVICE) is a nationwide, prospective registry with a longitudinal follow-up design investigating device implantations in 60 German centres. The present analysis of DEVICE focussed on perioperative complication rates and 1-year outcome of patients ≥75years (n=320) compared to younger patients (n=879) receiving a CRT device.

RESULTS

Comorbidities were more common in older patients (chronic kidney disease (CKD): 27.5% vs. 21.5%, p=0.029; atrial fibrillation (AF): 26.9% vs. 15.6%, p<0.001). Despite higher NYHA classes in the older age group, ejection fractions were comparable (27.2±7.1% ≥75years, 26.2±7.1% <75years, p=0.06). Perioperative complications and mortality rates did not show significant difference between groups. After new device implantation, absolute 1-year mortality was higher in older patients (11.0% ≥75years, 6.4% <75years, p=0.014), with a significantly lower proportion of cardiac deaths in the older group (p=0.05). Patients ≥75years being alive after 1year had lower response rates, with chronic kidney disease (OR 0.46, p<0.05) and smaller QRS complexes (OR 0.31, p<0.01) being particular risk factors for missing improvement of heart failure symptoms. As expected severe heart failure (NYHA IV) was a strong independent predictor of death (HR 1.95, p=0.01), whereas AF as underlying rhythm could be worked out as predictor for mortality especially in the younger patients (HR 2.31, p=0.002).

CONCLUSIONS

Patients ≥75years of age receiving a CRT device do not have a higher perioperative mortality and complication rate although comorbidities (CKD and AF) occur more frequently. The absolute 1-year mortality is higher; nevertheless, the proportion of cardiac deaths is even lower in the older patients reflecting a benefit of CRT in this group.

Is cardiac resynchronisation therapy feasible, safe and beneficial in the very elderly?

OBJECTIVE

To evaluate whether cardiac resynchronisation therapy (CRT) implantation was feasible and safe in octogenarians and the association with symptoms.

METHODS

Consecutive patients undergoing CRT implantation were recruited from two UK centers. Patients grouped according to age: < 80 & ≥ 80 years. Baseline demographics, complications and outcomes were compared between those groups.

RESULTS

A total of 439 patients were included in this study, of whom 26% were aged ≥ 80 years. Octogenarians more often received cardiac resynchronization therapy pacemaker in comparison to cardiac resynchronisation therapy-defibrillator. Upgrade from pacemaker was common in both groups (16% < 80 years vs. 22% ≥ 80 years, P = NS). Co-morbidities were similarly common in both groups (overall diabetes: 25%, atrial fibrillation: 23%, hypertension: 45%). More patient age ≥ 80 years had significant chronic kidney disease (CKD, estimated glomerular filtration rate < 45 mL/min per 1.73 m(2), 44% vs. 22%, P < 0.01). Overall complication rates (any) were similar in both groups (16% vs. 17%, P = NS). Both groups demonstrated symptomatic benefit. One-year mortality rates were almost four fold greater in octogenarians as compared with the younger cohort (13.9% vs. 3.7%, P < 0.01).

CONCLUSIONS

CRT appears to be safe in the very elderly despite extensive co-morbidity, and in particular frequent severe CKD. Symptomatic improvement appears to be meaningful. Strategies to increase the appropriate identification of elderly patients with CHF who are potential candidates for CRT are required.

Incidence, definition, diagnosis, and management of the cardiac resynchronization therapy nonresponder

PURPOSE OF REVIEW

Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in patients with mild-to-severe heart failure. However, up to 40% of CRT recipients are nonresponders. This review addresses important aspects with regard to the identification and management of CRT nonresponders.

RECENT FINDINGS

Mid-term clinical or echocardiographic nonresponse is associated with worse clinical outcomes during the extended follow-up. A number of predictors are indicative of CRT response, which include patient characteristics, electrical determinants, and imaging techniques from preimplant to postimplant period, and can be grouped as modifiable and nonmodifiable contributors to treatment response. Advanced age, male sex, ischemic cause, end-stage heart failure, inadequate electrical delay, and absence of mechanical dyssynchrony are regarded as unfavorable but nonmodifiable factors, for which considering underutilization of CRT by refining patient selection is reasonable. On the contrary, more efforts should be made to optimize patient management by correcting those modifiable factors, such as suboptimal medical therapy, uncontrolled atrial fibrillation, left ventricular lead dislodgement or inappropriate location, loss of biventricular capture, and lack of device optimization.

SUMMARY

Proper management and careful selection of CRT recipients will transform a proportion of treatment nonresponders into responders, which is vital to improve patients' outcome.

Does Age Influence Cardiac Resynchronization Therapy Use and Outcome?

OBJECTIVES

This study sought to describe the use of CRT-D and its association with survival for older patients.

BACKGROUND

Many patients who receive cardiac resynchronization therapy with defibrillator (CRT-D) in practice are older than those included in clinical trials.

METHODS

We identified patients undergoing ICD implantation in the National Cardiovascular Disease Registry (NCDR) ICD registry from 2006 to 2009, who also met clinical trial criteria for CRT, including left ventricular ejection fraction (LVEF) ≤35%, QRS ≥120 ms, and New York Heart Association (NYHA) functional class III or IV. NCDR registry data were linked to the social security death index to determine the primary outcome of time to death from any cause. We identified 70,854 patients from 1,187 facilities who met prior trial criteria for CRT-D. The mean age of the 58,147 patients receiving CRT-D was 69.4 years with 6.4% of patients age 85 or older. CRT use was 80% or higher among candidates in all age groups. Follow-up was available for 42,285 patients age ≥65 years at 12 months.

RESULTS

Receipt of CRT-D was associated with better survival at 1 year (82.1% vs. 77.1%, respectively) and 4 years (54.0% vs. 46.2% , respectively) than in those receiving only an ICD (p < 0.001). The CRT association with improved survival was not different for different age groups (p = 0.86 for interaction).

CONCLUSIONS

More than 80% of older patients undergoing ICD implantation who were candidates for a CRT-D received the combined device. Mortality in older patients undergoing ICD implantation was high but was lower for those receiving CRT-D.

The role of extracellular matrix in age-related conduction disorders: a forgotten player?

Cardiovascular aging is a physiological process gradually leading to structural degeneration and functional loss of all the cardiac and vascular components. Conduction system is also deeply influenced by the aging process with relevant reflexes in the clinical side. Age-related arrhythmias carry significant morbidity and mortality and represent a clinical and economical burden. An important and unjustly unrecognized actor in the pathophysiology of aging is represented by the extracellular matrix (ECM) that not only structurally supports the heart determining its mechanical and functional properties, but also sends a biological signaling regulating cellular function and maintaining tissue homeostasis. At the biophysical level, cardiac ECM exhibits a peculiar degree of anisotropy, which is among the main determinants of the conductive properties of the specialized electrical conduction system. Age-associated alterations of cardiac ECM are therefore able to profoundly affect the function of the conduction system with striking impact on the patient clinical conditions. This review will focus on the ECM changes that occur during aging in the heart conduction system and on their translation to the clinical scenario. Potential diagnostic and therapeutical perspectives arising from the knowledge on ECM age-associated alterations are further discussed.

Intermediate-term mortality and incidence of ICD therapy in octogenarians after cardiac resynchronization therapy

Background

Clinical outcomes of cardiac resynchronization therapy (CRT) in patients over the age of 80 have not been well described.

Methods

We retrospectively identified 96 consecutive patients ≥ 80 years old who underwent an initial implant or an upgrade to CRT, with or without defibrillator (CRT-D vs. CRT-P), at our institution between January 2003 and July 2008. The control cohort consisted of 177 randomly selected patients < 80 years old undergoing CRT implant during the same time period. The primary efficacy endpoint was all-cause mortality at 36 months, assessed by Kaplan-Meier time to first event curves.

Results

In the octogenarian cohort, mean age at CRT implant was 83.1 ± 2.9 years vs. 60.1 ± 8.8 years among controls (P < 0.001). Across both groups, 70% were male, mean left ventricular ejection fraction (LVEF) was 24.8% ± 14.1% and QRS duration was 154 ± 24.8 ms, without significant differences between groups. Octogenarians were more likely to have ischemic cardiomyopathy (74% vs. 37%, P < 0.001) and more likely to undergo upgrade to CRT instead of an initial implant (42% vs. 19%, P < 0.001). The rate of appropriate defibrillator shocks was lower among octogenarians (14% vs. 27%, P = 0.02) whereas the rate of inappropriate shocks was similar (3% vs. 6%, P = 0.55). At 36 months, there was no significant difference in the rate of all-cause mortality between octogenarians (11%) and controls (8%, P = 0.381).

Conclusion

Appropriately selected octogenarians who are candidates for CRT have similar intermediate-term mortality compared to younger patients receiving CRT.

Combined electrical and global markers of dyssynchrony predict clinical response to cardiac resynchronization therapy

AIM

To assess potential additional value of global left ventricular (LV) dyssynchrony markers in predicting cardiac resynchronization therapy (CRT) response in heart failure (HF) patients.

METHODS

We included 103 HF patients (mean age 67 ± 12 years, 83% male) who fulfilled the guidelines criteria for CRT treatment. All patients had undergone full clinical assessment, NT-proBNP and echocardiographic examination. Global LV dyssynchrony was assessed using total isovolumic time (t-IVT) and Tei index. On the basis of reduction in the NYHA class after CRT, patients were divided into responders and non-responders.

RESULTS

Prolonged t-IVT [0.878 (range, 0.802-0.962), p = 0.005], long QRS duration [0.978 (range, 0.960-0.996), p = 0.02] and high tricuspid regurgitation pressure drop [1.047 (range, 1.001-1.096), p = 0.046] independently predicted response to CRT. A t-IVT ≥ 11.6 s/min was 67% sensitive and 62% specific (AUC 0.69, p = 0.001) in predicting CRT response. Respective values for a QRS ≥ 151 ms were 66% and 62% (AUC 0.65, p = 0.01). Combining the two variables had higher specificity (88%) in predicting CRT response. In atrial fibrillation (AF) patients, only prolonged t-IVT [0.690 (range, 0.509-0.937), p = 0.03] independently predicted CRT response.

CONCLUSION

Combining prolonged t-IVT and the conventionally used broad QRS duration has a significantly higher specificity in identifying patients likely to respond to CRT. Moreover, in AF patients, only prolonged t-IVT independently predicted CRT response.

The impact of age on clinical outcomes following cardiac resynchronisation therapy

BACKGROUND

Cardiac resynchronisation therapy (CRT) is an established treatment for selected patients with symptomatic left ventricular (LV) systolic dysfunction. Heart failure (HF) is primarily a disease of the elderly; however, these patients are underrepresented in CRT trials. Our aim was to evaluate the impact of age on clinical outcomes following CRT.

METHODS

A consecutive series of 177 patients was identified and divided into those aged ≤ 7 5 years (n = 131, mean ± SD 62.1 ± 11.2 years) and those aged >75 years (n = 46, mean ± SD 80.7 ± 4.1 years). The primary end point was a composite of all-cause mortality or HF hospitalisation.

RESULTS

During a median ± IQR follow up of 28.5 ± 33.7 months, the event rate for the primary end point was significantly higher in the elderly compared to younger patients (20.1 vs. 11.1 %, respectively, logrank p = 0.020). This was mainly driven by an excess mortality rate among those aged >75 years (10 vs. 4.7%, respectively, logrank p = 0.018) whereas HF hospitalisation rates were similar between groups (10 vs. 6.4%, respectively, logrank p = 0.301). After adjusting for comorbidities and ICD status, the difference in the composite end point rates was attenuated and no longer significant (HR 1.580, 95% CI 0.899-2.778; p = 0.112 for >75 vs. ≤ 75 years). Notably, both groups demonstrated similar response rates to CRT in terms of symptomatic improvement, reverse LV remodelling and neurohormonal activation.

CONCLUSIONS

CRT is equally effective in the elderly as in younger patients to reduce adverse clinical outcomes. For those who fulfil the prerequisite selection criteria, it should be considered as a valid therapeutic option.