Mitral regurgitation in heart failure with preserved ejection fraction: The interplay of valve, ventricle, and atrium.

Mitral regurgitation (MR) is highly prevalent among patients with heart failure and preserved ejection fraction (HFpEF). Despite this combination being closely associated with unfavourable outcomes, it remains relatively understudied. This is partly due to the inherent heterogeneity of patients with HFpEF. To address this gap, dissecting HFpEF into mechanism-based phenotypes may offer a promising avenue for advancing our comprehension of these complex intertwined conditions. This review employs the validated CircAdapt model to explore the haemodynamic implications of moderate to severe MR across a well-defined spectrum of myocardial disease, characterized by impaired relaxation and reduced myocardial compliance. Both heart failure and mitral valve disease share overlapping symptomatology, primarily attributed to elevated pulmonary pressures. The intricate mechanisms contributing to these elevated pressures are multifaceted, potentially influenced by diastolic dysfunction, left atrial myopathy, and MR. Accurate evaluation of the haemodynamic and clinical impact of MR necessitates a comprehensive approach, taking into account the characteristics of both the left atrium and left ventricle, as well as their intricate interactions, which may currently be underemphasized in diagnostic practice. This holistic assessment is imperative for enhancing our understanding and refining therapeutic strategies within this patient cohort.

Sodium loading in ambulatory patients with heart failure with reduced ejection fraction: Mechanistic insights into sodium handling.

AIMS: Sodium restriction was not associated with improved outcomes in heart failure patients in recent trials. The skin might act as a sodium buffer, potentially explaining tolerance to fluctuations in sodium intake without volume overload, but this is insufficiently understood. Therefore, we studied the handling of an increased sodium load in patients with heart failure with reduced ejection fraction (HFrEF). METHODS AND RESULTS: Twenty-one ambulatory, stable HFrEF patients and 10 healthy controls underwent a 2-week run-in phase, followed by a 4-week period of daily 1.2 g (51 mmol) sodium intake increment. Clinical, echocardiographic, 24-h urine collection, and bioelectrical impedance data were collected every 2 weeks. Blood volume, skin sodium content, and skin glycosaminoglycan content were assessed before and after sodium loading. Sodium loading did not significantly affect weight, blood pressure, congestion score, N-terminal pro-brain natriuretic peptide, echocardiographic indices of congestion, or total body water in HFrEF (all p > 0.09). There was no change in total blood volume (4748 ml vs. 4885 ml; p = 0.327). Natriuresis increased from 150 mmol/24 h to 173 mmol/24 h (p = 0.024), while plasma renin decreased from 286 to 88 µU/L (p = 0.002). There were no significant changes in skin sodium content, total glycosaminoglycan content, or sulfated glycosaminoglycan content (all p > 0.265). Healthy controls had no change in volume status, but a higher increase in natriuresis without any change in renin. CONCLUSIONS: Selected HFrEF patients can tolerate sodium loading, with increased renal sodium excretion and decreased neurohormonal activation.

Arrythmia-Mediated Valvular Heart Disease.

The aging population is rising at record pace worldwide. Along with it, a steep increase in the prevalence of atrial fibrillation and heart failure with preserved ejection fraction is to be expected. Similarly, both atrial functional mitral and tricuspid regurgitation (AFMR and AFTR) are increasingly observed in daily clinical practice. This article summarizes all current evidence regarding the epidemiology, prognosis, pathophysiology, and therapeutic options. Specific attention is addressed to discern AFMR and AFTR from their ventricular counterparts, given their different pathophysiology and therapeutic needs.

Reduced Left Atrial Appendage Flow Is Associated With Future Atrial Fibrillation After Cryptogenic Stroke.

BACKGROUND: Hemostasis within the left atrial appendage (LAA) is a common cause of stroke, especially in patients with atrial fibrillation (AF). Although LAA flow provides insights into LAA function, its potential for predicting AF has yet to be established. The aim of this study was to explore whether LAA peak flow velocities early after cryptogenic stroke are associated with future AF on prolonged rhythm monitoring. METHODS: A total of 110 patients with cryptogenic stroke were consecutively enrolled and underwent LAA pulsed-wave Doppler flow assessment using transesophageal echocardiography within the early poststroke period. Velocity measurements were analyzed offline by an investigator blinded to the results. Prolonged rhythm monitoring was conducted on all participants via 7-day Holter and implantable cardiac monitoring devices, with follow-up conducted over a period of 1.5 years to determine the incidence of AF. The end point of AF was defined as irregular supraventricular rhythm with variable RR interval and no detectable P waves lasting ≥30 sec during rhythm monitoring. RESULTS: During a median follow-up period of 539 days (interquartile range, 169-857 days), 42 patients (38%) developed AF, with a median time to AF diagnosis of 94 days (interquartile range, 51-487 days). Both LAA filling velocity and LAA emptying velocity (LAAev) were lower in patients with AF (44.3 ± 14.2 and 50.7 ± 13.3 cm/s, respectively) compared with patients without AF (59.8 ± 14.0 and 76.8 ± 17.3 cm/sec, respectively; P < .001 for both). LAAev was most strongly associated with future AF, with an area under the receiver operating characteristic curve of 0.88 and an optimal cutoff value of 55 cm/sec. Age and mitral regurgitation were independent determinants of reduced LAAev. CONCLUSIONS: Impaired LAA peak flow velocities (LAAev < 55 cm/sec) in patients with cryptogenic stroke are associated with future AF. This may facilitate the selection of appropriate candidates for prolonged rhythm monitoring to improve its diagnostic accuracy and implementation.

Sex Differences in Extensive Mitral Annular Calcification With Associated Mitral Valve Dysfunction.

Mitral annular calcification (MAC)-related mitral valve (MV) dysfunction is an increasingly recognized entity, which confers a high burden of morbidity and mortality. Although more common among women, there is a paucity of data regarding how the phenotype of MAC and the associated adverse clinical implications may differ between women and men. A total of 3,524 patients with extensive MAC and significant MAC-related MV dysfunction (i.e., transmitral gradient ≥3 mm Hg) were retrospectively analyzed from a large institutional database, with the goal of defining gender differences in clinical and echocardiographic characteristics and the prognostic importance of MAC-related MV dysfunction. We stratified patients into low- (3 to 5 mm Hg), moderate- (5 to 10 mm Hg), and high- (≥10 mm Hg) gradient groups and analyzed the gender differences in phenotype and outcome. The primary outcome was all-cause mortality, assessed using adjusted Cox regression models. Women represented the majority (67%) of subjects, were older (79.3 ± 10.4 vs 75.5 ± 10.9 years, p <0.001) and had a lower burden of cardiovascular co-morbidities than men. Women had higher transmitral gradients (5.7 ± 2.7 vs 5.3 ± 2.6 mm Hg, p <0.001), more concentric hypertrophy (49% vs 33%), and more mitral regurgitation. The median survival was 3.4 years (95% confidence interval 3.0 to 3.6) among women and 3.0 years (95% confidence interval 2.6 to 4.5) among men. The adjusted survival was worse among men, and the prognostic impact of the transmitral gradient did not differ overall by gender. In conclusion, we describe important gender differences among patients with MAC-related MV dysfunction and show worse adjusted survival among men; although, the adverse prognostic impact of the transmitral gradient was similar between men and women.

Mitral Valve Dysfunction in Patients With Annular Calcification: JACC Review Topic of the Week.

Mitral annular calcification (MAC) is a common clinical finding and is associated with adverse clinical outcomes, but the clinical impact of MAC-related mitral valve (MV) dysfunction remains underappreciated. Patients with MAC frequently have stenotic, regurgitant, or mixed valvular disease, and this valvular dysfunction is increasingly recognized to be independently associated with worse prognosis. MAC-related MV dysfunction is a distinct pathophysiologic entity, and importantly much of the diagnostic and therapeutic paradigm from published rheumatic MV disease research cannot be applied in this context, leaving important gaps in our knowledge. This review summarizes the current epidemiology, pathophysiology, diagnosis, and classification of MAC-related MV dysfunction and proposes both an integrative definition and an overarching approach to this important and increasingly recognized clinical condition.

Acute valvular emergencies.

Acute valvular emergencies represent an important cause of cardiogenic shock. However, their clinical presentation and initial diagnostic testing are often non-specific, resulting in delayed diagnosis. Moreover, metabolic disarray or haemodynamic instability may result in too great a risk for emergent surgery. This review will focus on the aetiology, clinical presentation, diagnostic findings, and treatment options for patients presenting with native acute left-sided valvular emergencies. In addition to surgery, options for medical therapy, mechanical circulatory support, and novel percutaneous interventions are discussed.

Alterations in Human Mitral Valve Mechanical Properties Secondary to Left Ventricular Remodeling: A Biaxial Mechanical Study.

Secondary mitral regurgitation occurs when a left ventricular problem causes leaking of the mitral valve. The altered left ventricular geometry changes the orientation of the subvalvular apparatus, thereby affecting the mechanical stress on the mitral valve. This in turn leads to active remodeling of the mitral valve, in order to compensate for the ventricular remodeling. In this study, a biomechanical analysis was performed on eight human mitral valves with secondary mitral regurgitation and ten healthy human mitral valves to better understand this pathophysiology and its effect on the mechanical properties of these tissues. Samples were obtained from the anterior and posterior leaflet and used for planar biaxial mechanical experiments. Uniaxial experiments were performed on four groups of mitral valve chords: anterior basal, anterior marginal, posterior basal and posterior marginal chords. The mechanical response of the mitral valve leaflets was fitted to the May-Newman and Yin constitutive model, whereas the material parameters of the third order Ogden model were determined for the chord samples. Next, stiffnesses calculated at low and high stress levels were statistically analyzed. Leaflet samples with secondary mitral regurgitation showed a small thickness increase and a change in anisotropy index compared to healthy control valves. Diseased leaflets were more compliant circumferentially and stiffer radially, resulting in anisotropic samples with the radial direction being stiffest. In addition, chord samples were slightly thicker and less stiff at high stress in secondary mitral regurgitation, when grouped per leaflet type and insertion region. These results confirm mechanical alterations due to the pathophysiological valvular changes caused by left ventricular remodeling. It is important that these changes in mechanical behavior are incorporated into computational models of the mitral valve.

The MADIT-ICD benefit score helps to select implantable cardioverter-defibrillator candidates in cardiac resynchronization therapy.

AIMS: The aim of this study is to evaluate whether the MADIT-ICD benefit score can predict who benefits most from the addition of implantable cardioverter-defibrillator (ICD) to cardiac resynchronization therapy (CRT) in real-world patients with heart failure with reduced ejection fraction (HFrEF) and to compare this with selection according to a multidisciplinary expert centre approach. METHODS AND RESULTS: Consecutive HFrEF patients who received a CRT for a guideline indication at a tertiary care hospital (Ziekenhuis Oost-Limburg, Genk, Belgium) between October 2008 and September 2016, were retrospectively evaluated. The MADIT-ICD benefit groups (low, intermediate, and high) were compared with the current multidisciplinary expert centre approach. Endpoints were (i) sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) and (ii) non-arrhythmic mortality. Of the 475 included patients, 165 (34.7%) were in the lowest, 220 (46.3%) in the intermediate, and 90 (19.0%) in the highest benefit group. After a median follow-up of 34 months, VT/VF occurred in 3 (1.8%) patients in the lowest, 9 (4.1%) in the intermediate, and 13 (14.4%) in the highest benefit group (P < 0.001). Vice versa, non-arrhythmic death occurred in 32 (19.4%) in the lowest, 32 (14.6%) in the intermediate, and 3 (3.3%) in the highest benefit group (P = 0.002). The predictive power for ICD benefit was comparable between expert multidisciplinary judgement and the MADIT-ICD benefit score: Uno's C-statistic 0.69 vs. 0.69 (P = 0.936) for VT/VF and 0.62 vs. 0.60 (P = 0.790) for non-arrhythmic mortality. CONCLUSION: The MADIT-ICD benefit score can identify who benefits most from CRT-D and is comparable with multidisciplinary judgement in a CRT expert centre.

Impact of Pulmonary Hypertension on Outcomes in Patients With Mitral Annular Calcium and Associated Mitral Valve Dysfunction.

The prevalence of mitral annular calcium (MAC) is increasing in our aging population. However, data regarding prognostication in MAC-related mitral valve (MV) disease remain limited. This retrospective observational study aims to explore the prognostic impact of systolic pulmonary artery pressure (SPAP) in MAC-related MV dysfunction and define its determinants. We identified 4,384 patients (mean age 78 ± 11 years and 69% female) with MAC-related MV dysfunction (documented transmitral gradient ≥3 mm Hg) from a large institutional echocardiographic database between 2001 and 2019. In Cox regression analysis, higher SPAP strongly associated with all-cause mortality, independent of cardiovascular risk factors and indices of MV dysfunction (adjusted hazard ratio 1.22 per 10 mm Hg SPAP increase, 95% confidence interval 1.17 to 1.27). Patients with SPAP ≥50 mm Hg had significantly higher mortality compared with SPAP <50 mm Hg (log-rank p <0.001), a finding that was consistent across different transmitral gradient subgroups (≤5, 5 to 10, and ≥10 mm Hg). Independent determinants of SPAP included the mean transmitral gradient, mitral regurgitation severity, left ventricular ejection fraction, and ≥moderate aortic stenosis (adjusted p <0.05), and atrial fibrillation and left atrial dimension. The impact of concomitant mitral regurgitation on SPAP decreased at higher transmitral gradients and was no longer significant at gradients ≥10 mm Hg (p = 0.100). In conclusion, SPAP strongly associates with mortality in MAC, independent of cardiovascular risk factors and indices of MAC-related MV dysfunction. These findings suggest an incremental role for SPAP in the risk stratification and prognostication in this increasingly prevalent condition with expanding the scope of possible interventions.

Mitral Annular Dynamics in AF Versus Sinus Rhythm: Novel Insights Into the Mechanism of AFMR.

OBJECTIVES: This study aimed to investigate mitral annular dynamics in atrial fibrillation (AF) and after sinus rhythm restoration, and to assess the relationship between annular dynamics and mitral regurgitation (MR). BACKGROUND: AF can be associated with MR that improves after sinus rhythm restoration. Mechanisms underlying this atrial functional MR (AFMR) are ill-understood and generally attributed to left atrial remodeling. METHODS: Fifty-three patients with persistent AF and normal left ventricular ejection fraction were prospectively examined by means of 3-dimensional transesophageal echocardiography before, immediately after, and 6 weeks after electric cardioversion to sinus rhythm. Annular motion was assessed during AF and in sinus rhythm with the use of 3-dimensional analysis software, and the relationship with MR severity was explored. RESULTS: During AF and immediately after sinus rhythm restoration, the mitral annulus behaved relatively adynamically, with an overall change in annular area of 10.3% (95% CI: 8.7%-11.8%) and 12.2% (95% CI: 10.6%-13.8%), respectively. At follow-up, a significant increase in annular dynamics (19.0%; 95% CI: 17.4%-20.6%; P < 0.001) was observed, owing predominantly to an increase in presystolic contraction (P < 0.001). The effective regurgitant orifice area decreased from 0.15 cm2 (0.10-0.23 cm2) during AF to 0.09 cm2 (0.05-0.12 cm2) at follow-up (P < 0.001) in the total cohort, and from 0.27 (0.23-0.33) to 0.16 (0.12-0.29) in the subgroup with effective regurgitant orifice area (EROA) ≥0.20 cm2. The change in presystolic annular motion was the only independent determinant of the decrease in MR severity (P = 0.027), by optimizing annular-leaflet imbalance. Patients with more pronounced blunting of presystolic dynamics had a higher EROA (P < 0.001), because of a lower total-to-closed leaflet area ratio (P < 0.001) at each point in time. This ratio was the strongest independent determinant of AFMR severity (adjusted P = 0.003). CONCLUSIONS: Mitral annular dynamics are impaired in AF, with blunted presystolic narrowing that contributes to AFMR. Sinus rhythm restoration allows gradual recovery of presystolic annular dynamics. Improved annular dynamics decrease AFMR severity by optimizing annular-leaflet imbalance, regardless of LA remodeling.

Outcome and durability of mitral valve annuloplasty in atrial secondary mitral regurgitation.

OBJECTIVES: Atrial secondary mitral regurgitation (ASMR) is a clinically distinct form of Carpentier type I mitral regurgitation (MR), rooted in excessive atrial and mitral annular dilation in the absence of left ventricular dysfunction. Mitral valve annuloplasty (MVA) is expected to provide a more durable solution for ASMR than for ventricular secondary MR (VSMR). Yet data on MR recurrence and outcome after MVA for ASMR are scarce. This study sought to investigate surgical outcomes and repair durability in patients with ASMR, as compared with a contemporary group of patients with VSMR. METHODS: Clinical and echocardiographic data from consecutive patients who underwent MVA to treat ASMR or VSMR in an academic centre were retrospectively analysed. Patient characteristics, operative outcomes, time to recurrence of ≥moderate MR and all-cause mortality were compared between patients with ASMR versus VSMR. RESULTS: Of the 216 patients analysed, 97 had ASMR opposed to 119 with VSMR and subvalvular leaflet tethering. Patients with ASMR were typically female (68.0% vs 33.6% in VSMR, p<0.001), with a history of atrial fibrillation (76.3% vs 33.6% in VSMR, p<0.001), paralleling a larger left atrial size (p<0.033). At a median follow-up of 3.3 (IQR 1.0-7.3) years, recurrence of ≥moderate MR was significantly lower in ASMR versus VSMR (7% vs 25% at 2 years, overall log-rank p=0.001), also when accounting for all-cause death as competing risk (subdistribution HR 0.50 in ASMR, 95% CI 0.29 to 0.88, p=0.016). Moreover, ASMR was associated with better overall survival compared with VSMR (adjusted HR 0.43 95% CI 0.22 to 0.82, p=0.011), independent from baseline European System for Cardiac Operative Risk Evaluation II surgical risk score. CONCLUSION: Prognosis following MVA to treat ASMR is better, compared with VSMR as reflected by lower all-cause mortality and MR recurrence. Early distinction of secondary MR towards underlying ventricular versus atrial disease has important therapeutic implications.

Atrial Fibrillation Population Screening.

Atrial fibrillation (AF) is associated with adverse outcomes. Screening may lead to earlier recognition and treatment of asymptomatic AF. However, most evidence regarding AF applies to clinical AF, with symptoms or electrocardiographic diagnosis. Whether this evidence can be translated toward subclinical AF, without symptoms and detected by novel, more continuous screening devices is uncertain. The diagnostic yield of screening is determined by the screening population, tool, duration and frequency. Longer and more frequent screening in a higher risk population leads to more effective screening. New devices based on photoplethysmography and single-lead electrocardiography increase convenience and the likelihood of cost-effectiveness.

Left ventricular function recovery after ST-elevation myocardial infarction: correlates and outcomes.

BACKGROUND: Contemporary data on left ventricular function (LVF) recovery in patients with left ventricular dysfunction after ST-elevation myocardial infarction (STEMI) are scarce and to date, no comparison has been made with patients with a baseline normal LVF. This study examined predictors of LVF recovery and its relation to outcomes in STEMI. METHODS: Patients presenting with STEMI between January 2010 and December 2016 were categorized in three groups after 3 months according to left ventricular ejection fraction (EF): (i) baseline normal LVF (EF ≥ 50% at baseline); (ii) recovered LVF (EF < 50% at baseline and ≥ 50% after 3 months); and (iii) reduced LVF (EF < 50% at baseline and after 3 months). Heart failure hospitalization, all-cause mortality and cardiovascular mortality were compared between the three groups. RESULTS: Of 577 patients, 341 (59%) patients had a baseline normal LVF, 112 (19%) had a recovered LVF and 124 (22%) had a reduced LVF. Independent correlates of LVF recovery were higher baseline EF, lower peak troponin and cardiac arrest. After median 5.8 years, there was no difference in outcomes between patients with LVF recovery and baseline normal LVF. In contrast, even after multivariate adjustment, patients with persistently reduced LVF had a higher risk for heart failure hospitalization (HR 5.00; 95% CI 2.17-11.46) and all-cause mortality (HR 1.87; 95% CI 1.11-3.16). CONCLUSION: In contemporary treated STEMI patients, prognosis is significantly worse in those with a persistently reduced LVF after 3 months, compared with patients with a baseline normal LVF and those with LVF recovery.

Diuretic response and effects of diuretic omission in ambulatory heart failure patients on chronic low-dose loop diuretic therapy.

AIMS: To study loop diuretic response and effect of loop diuretic omission in ambulatory heart failure (HF) patients on chronic low-dose loop diuretics. METHODS AND RESULTS: Urine collections were performed on two consecutive days in 40 ambulatory HF patients with 40-80 mg furosemide (day 1 with loop diuretic; day 2 without loop diuretic). Three phases were collected each day: (i) first 6 h; (ii) rest of the day; and (iii) night. On the day of loop diuretic intake, the total natriuresis was 125.9 (86.9-155.0) mmol/24 h and urine output was 1650 (1380-2025) mL/24 h. There was a clear loop diuretic response with a natriuresis of 9.4 (6.7-15.9) mmol/h and a urine output of 117 (83-167) mL/h during the first 6 h, followed by a significant drop in natriuresis and urine output during the rest of the day [2.6 (1.8-4.8) mmol/h and 55 (33-71) mL/h] and night [2.2 (1.6-3.5) mmol/h and 44 (34-73) mL/h]. On day 2, after loop diuretic omission, the natriuresis and urine output remained similarly low the entire day, resulting in a 50% reduction in natriuresis [55.1 (33.5-77.7) mmol/24 h; P < 0.001] and a 31% reduction in urine output [1035 (875-1425) mL/24 h; P < 0.001] compared with the day of loop diuretic intake. CONCLUSION: Patients with HF on chronic loop diuretic treatment still have a clear diuretic response phase, while loop diuretic omission leads to a significant drop in natriuresis and urine output, arguing against routine cessation of low-dose loop diuretics.

Left Atrial Mechanics Assessed Early during Hospitalization for Cryptogenic Stroke Are Associated with Occult Atrial Fibrillation: A Speckle-Tracking Strain Echocardiography Study.

BACKGROUND: Occult atrial fibrillation (AF) is an important contributor to cryptogenic stroke, yet remains difficult to unmask at presentation. This study investigated the predictive value of left atrial (LA) mechanics by strain echocardiography during stroke hospitalization for the presence of AF as detected on early 30-day monitoring and routine clinical follow-up. METHODS: Left atrial mechanics were studied by strain echocardiography in a retrospective cohort of 191 patients with cryptogenic stroke and 30-day mobile cardiac outpatient telemetry poststroke to diagnose AF. After this, AF was diagnosed via routine clinical follow-up. The independent and incremental value of measures of LA size and mechanics (i.e., strain and strain rate in the reservoir, conduit, and booster pump phase) to predict AF on top of clinical characteristics was assessed. RESULTS: Of 191 patients, 15% (n = 28) developed AF, of which 10 were observed during 30-day mobile cardiac outpatient telemetry and 18 were observed at a median follow-up of 25 (interquartile range, 10-43) months. Median time from embolic stroke to strain echocardiography was 1 day (interquartile range, 1-2 days). Left atrial mechanics were significantly worse in AF (P < .05 for all), despite largely similar baseline cardiovascular risk profile. Booster pump strain rate was the strongest predictor for AF, independent of age, LA volume index, E/e', and reservoir strain (odds ratio = 2.88 per SD increase; 95% confidence interval, 1.29-6.41; P = .010). Adding LA strain reservoir strain and booster pump function significantly enhanced a multivariate model to predict AF. Freedom from AF was significantly lower in subjects with a booster pump strain rate (at stroke presentation) worse than -0.67 sec-1, as derived from receiver operator curve analysis (P < .001). CONCLUSIONS: Left atrial mechanics and particularly the LA booster pump function assessed early during hospitalization for cryptogenic stroke can identify patients at greater likelihood of future diagnosis of AF. These findings could in part relate to LA mechanical stunning after spontaneous cardioversion, which-when identified by early strain echocardiography-can inform further risk stratification and decision-making.

LA Mechanics in Decompensated Heart Failure: Insights From Strain Echocardiography With Invasive Hemodynamics.

OBJECTIVES: The aim of this study was to assess the effect of congestion and decongestive therapy on left atrial (LA) mechanics and to determine the relationship between LA improvement after decongestive therapy and clinical outcome in immediate or chronic heart failure with reduced ejection fraction (HFrEF). BACKGROUND: LA mechanics are affected by volume/pressure overload in decompensated HFrEF. METHODS: A total of 31 patients with HFrEF and immediate heart failure (age 64 ± 15 years, 74% male, left ventricular ejection fraction 20 ± 12%) underwent serial echocardiography during decongestive therapy with simultaneous hemodynamic monitoring. LA function was assessed by strain (rate) imaging. Patients were re-evaluated 6 weeks after discharge and prospectively followed up for the composite endpoint of heart failure readmission and all-cause mortality. RESULTS: LA reservoir function was markedly reduced at baseline and improved with decongestion (peak atrial longitudinal strain from 6.4 ± 2.2% to 8.8 ± 3.0% and strain rate from 0.29 ± 0.11 s-1 to 0.38 ± 0.13 s-1), independent of changes in left ventricular global longitudinal strain, LA end-diastolic volume, and mitral regurgitation severity (p < 0.001). Both measures continued to rise at 6 weeks (up to 13.4 ± 6.1% and 0.50 ± 0.19 s-1, respectively; p < 0.001). LA pump strain rate only increased 6 weeks after discharge (-0.25 ± 0.12 s-1 to -0.55 ± 0.29 s-1; p < 0.010). Changes in LA mechanics correlated with changes in wedge pressure (r = -0.61; p < 0.001). Lower peak atrial longitudinal strain values after decongestion were associated with increased risk for the composite endpoint of heart failure and mortality (p < 0.019). CONCLUSIONS: LA reservoir and booster function, while severely impaired during immediate decompensation, significantly improve during and after decongestive therapy. Poor LA reservoir function after decongestion is associated with worse outcome.

The Detrimental Effect of RA Pacing on LA Function and Clinical Outcome in Cardiac Resynchronization Therapy.

OBJECTIVES: This study assessed the impact of right-atrial (RA) pacing on left-atrial (LA) physiology and clinical outcome. BACKGROUND: Data for the effects of RA pacing on LA synchronicity, function, and structure after cardiac resynchronization therapy (CRT) are scarce. METHODS: The effect of RA pacing on LA function, morphology, and synchronicity was assessed in a prospective imaging cohort of heart failure (HF) patients in sinus rhythm with a guideline-based indication for CRT. Additionally, in a retrospective outcome cohort of consecutive HF patients undergoing CRT implantation, the relationship to RA pacing was assessed using various outcome endpoints. High versus low atrial pacing burden was defined as atrial pacing above or below 50% in both cohorts. RESULTS: A total of 36 patients were included in the imaging cohort (68 ± 11 years of age). Six months after CRT, patients with high RA pacing burden showed less improvement in LA maximum and minimum volumes and total emptying fraction (p < 0.05). Peak atrial longitudinal strain and reservoir and booster strain rates but not conduit strain rate improved after CRT in patients with low RA pacing burden but worsened in patients with high RA pacing burden (p < 0.05 for all). A high RA pacing burden induced significant intra-atrial dyssynchrony (maximum opposing wall delay: 44 ± 13 ms vs. 97 ± 17 ms, respectively; p = 0.022). A total of 569 patients were included in the outcome cohort. After covariate adjustments were made, a high RA pacing burden was associated with reduced LV reverse remodeling (ß = 8.738; 95% confidence interval [CI]: 3.101 to 14.374; p = 0.002) and new-onset or recurrent atrial fibrillation (41% vs. 22%, respectively, at a median of 31 months [range 22 to 44 months follow-up]; p < 0.001). There were no differences in time to first HF hospitalization or all-cause mortality (p = 0.185) after covariate adjustment. However, in a recurrent event analysis, HF readmissions were more common in patients exposed to a high RA pacing burden (p = 0.003). CONCLUSIONS: RA pacing in CRT patients negatively influences LA morphology, function, and synchronicity, which is associated with worse clinical outcome, including diminished LV reverse remodeling, increased risk for new-onset or recurrent AF and heart failure readmission. Strategies reducing RA pacing burden may be warranted.