Relation of Myocardial Work Indexes and Forward Flow Reserve in Patients With Significant Secondary Mitral Regurgitation Undergoing Transcatheter Mitral Valve Repair.

Left ventricular (LV) myocardial work (LVMW) indexes have shown incremental value over LV ejection fraction and were found to have prognostic significance in patients with secondary mitral regurgitation. We therefore aimed to investigate the association between LVMW indexes and forward flow reserve in patients with secondary mitral regurgitation, treated with transcatheter edge-to-edge repair (TEER). LVMW indexes were evaluated at baseline and forward stroke volume index (FSVI) was evaluated at baseline and 6-month follow-up after TEER. Patients were divided in 2 groups: improvers (improvement in FSVI ≥20%) and nonimprovers (improvement in FSVI <20%). A total of 70 patients (median age 76 years, 59% men) were included. FSVI was the only echocardiographic parameter that improved after TEER. There was a significant decrease in LV global longitudinal strain in the nonimprovers (p = 0.002) but not in the improvers (p = 0.177). Global work index and global constructive work worsened in nonimprovers (p = 0.005 and p = 0.004, respectively), whereas no difference was seen in these indexes in improvers (p = 0.093 and p = 0.112, respectively). Global work efficiency remained independently associated with forward flow reserve after adjusting for a variety of potential confounders. In conclusion, FSVI nonimprovers demonstrated worsening of LV systolic function after TEER compared with improvers, in whom LV systolic function remained stable. Global work efficiency was associated with FSVI improvement after TEER, independent of LV systolic function.

Prognostic Implications of Left Ventricular Myocardial Work Indices in Patients With Secondary Mitral Regurgitation.

BACKGROUND: Assessment of left ventricular (LV) function in patients with secondary mitral regurgitation (SMR) remains challenging but is an important parameter for risk stratification. The association of LV myocardial work components (work index [GWI], constructive [GCW] and wasted [GWW] work, and work efficiency) derived from pressure-strain loops obtained with speckle tracking echocardiography, and all-cause mortality in patients with SMR was investigated. METHODS: LV myocardial GWI, GCW, GWW, and global work efficiency were measured with speckle tracking strain echocardiography in 373 patients (72% men, median age 68 years) with various grades of SMR. All-cause mortality was the primary end point. RESULTS: Mild SMR was observed in 143 patients, 128 had moderate SMR, and 102 had severe SMR. Patients with severe SMR had the largest LV volumes and the worst LV ejection fraction and LV global longitudinal strain. In patients with severe SMR, LV GWI and GCW were more impaired (500 mm Hg% versus 680 mm Hg% P=0.024 and 678 mm Hg% versus 851 mm Hg% P=0.006, respectively), while GWW was lower (130 mm Hg% versus 260 mm Hg% P<0.001, respectively) and global work efficiency was significantly higher (82% versus 76%, P=0.001) compared with patients with mild SMR. After a median follow-up of 56 months, 161 patients died. LV GWI≤500 mm Hg%, LV GCW≤750 mm Hg%, and LV GWW<300 mm Hg% were independently associated with excess mortality. CONCLUSIONS: Patients with severe SMR had the worst LV GWI and LV GCW but better LV GWW and global work efficiency reflecting the unloading of the LV in the low-pressure left atrial chamber. These parameters were independently associated with worse long-term survival in patients with SMR.

Influence of Chronic Obstructive Pulmonary Disease on Atrial Mechanics by Speckle Tracking Echocardiography in Patients With Atrial Fibrillation.

The present study aimed to examine differences in left- and right atrial characteristics between atrial fibrillation (AF) patients with and without chronic obstructive pulmonary disease (COPD). For this, 420 patients (mean age 68 ± 10 years, 73% female) with first diagnosis of AF and baseline echocardiography were included. Of these, 143 COPD patients were compared with 277 patients without COPD matched by age, gender and body surface area. Additionally 38 healthy controls without cardiovascular risk factors, matched for age, were included. For all 3 groups, left atrial (LA) volumes and diameter, LA reservoir strain (LASr), left ventricular ejection fraction (LVEF), right atrial (RA) area and diameter, RA reservoir strain (RASr) and tricuspid annular plane systolic excursion were evaluated on transthoracic echocardiography. Baseline characteristics were similar in patients with and without COPD except for smoking and a history of heart failure (42% vs 11%, p < 0.001 and 48% vs 37%, p = 0.036 for COPD and non-COPD patients, respectively). Also, COPD patients less often used ß-blockers (63% vs 75%, p = 0.017). There were no significant differences in LVEF, LA volume and RA area between COPD and non-COPD patients. Compared to the controls, AF patients had impaired LVEF, LASr and RASr. Only RASr was significantly worse in COPD patients as compared to non-COPD patients (15.3% [9.0 to 25.1] vs 19.6% [11.8 to 28.5], p = 0.013). Additionally, a trend towards worse RASr was observed with increasing COPD severity. In conclusion, AF patients with concomitant COPD have more impaired RA function compared to patients without COPD but with similar atrial size and LA function.

Prognostic implications of global, left ventricular myocardial work efficiency before cardiac resynchronization therapy.

AIMS: Cardiac resynchronization therapy (CRT) restores mechanical efficiency to the failing left ventricular (LV) by resynchronization of contraction. Global, LV myocardial work efficiency (GLVMWE) can be quantified non-invasively with echocardiography. The prognostic implication of GLVMWE remains unexplored, and we therefore related GLVMWE before CRT to long-term prognosis. METHODS AND RESULTS: Data were analysed from an ongoing registry of patients with Class I indications for CRT. GLVMWE was defined as the ratio of constructive work in all LV segments, divided by the sum of constructive and wasted work in all LV segments, as a percentage. It was derived from speckle tracking strain echocardiography and non-invasive blood pressure measurements, taken pre-CRT. Patients were dichotomized according to baseline, median GLVMWE [75%; interquartile range (IQR) 66-81%]. A total of 153 patients (66 ± 10 years, 72% male, 48% ischaemic heart disease) were analysed. After a median follow-up of 57 months (IQR 28-76 months), 31% of patients died. CRT recipients with less efficient baseline energetics (GLVMWE <75%) demonstrated lower event rates than patients with more efficient baseline energetics (GLVMWE ≥75%) (log-rank test, P = 0.029). On multivariable analysis, global LV wasted work ratio <75% pre-CRT was independently associated with a decreased risk of all-cause mortality (hazard ratio 0.48, 95% confidence interval 0.25-0.92; P = 0.027), suggesting that the potential for improvement in LV efficiency is important for CRT benefit. CONCLUSION: GLVMWE can be derived non-invasively from speckle tracking strain echocardiography and non-invasive blood pressure recordings. A lower GLVMWE before CRT is independently associated with improved long-term outcome.

Impact of atrial fibrillation on improvement of functional mitral regurgitation in cardiac resynchronization therapy.

BACKGROUND: Functional mitral regurgitation (FMR) and atrial fibrillation (AF) are frequent heart failure (HF) complications. Cardiac resynchronization therapy (CRT) can improve FMR; however, little is known about the influence of AF on FMR improvement. OBJECTIVE: The purpose of this study was to investigate the mechanisms and impact of baseline AF on FMR improvement after CRT. METHODS: CRT recipients with HF, AF, or sinus rhythm (SR) at baseline with moderate or severe FMR, were included from an ongoing registry. Left atrial (LA), mitral annular (MA), and left ventricular (LV) dimensions were evaluated echocardiographically. FMR improvement was defined as ≥1 grade decrease from baseline to 6-month follow-up. Clinical and echocardiographic measurements were performed at baseline and 6-month follow-up. RESULTS: A total of 419 patients (age 66 ± 8 years; 73% male) were analyzed. At 6-month follow-up, FMR improved in 145 patients (45.6%) with SR vs 31 of AF patients (30.7%) (P = .011). Despite similar LV reverse remodeling at 6 months after CRT (LV end-systolic volume decreased by 32.1 ± 43.2 mL in the SR group and by 27.7 ± 6.3 mL in those with AF; P = .353), patients with SR exhibited smaller LA volumes (63.0 ± 26.5 mL vs 103.1 ± 41.0 mL; P <.001) and MA diameters (42.3 ± 5.6 mm vs 46.1 ± 5.8 mm; P <.001) compared to AF patients. CONCLUSION: FMR improvement is more common in CRT recipients in SR vs AF, despite a similar degree of LV remodeling. LA volume and MA diameter are greater in the AF group, causing the negative impact of AF on FMR improvement in CRT, as well as indicating a potential therapeutic target (ie, AF rhythm control).