Left atrial strain and distensibility in relation to left ventricular dysfunction and prognosis in aortic stenosis.

OBJECTIVE: To test the relationship between left atrial (LA) distensibility (LAD), LA strain (LAS), and left ventricular (LV) dysfunction and prognosis in aortic stenosis (AS). METHODS: Transthoracic Doppler echocardiography was performed prospectively in 102 consecutive patients with AS (77 with severe, 25 with moderate, mean age 77 years). LA volume was calculated by the area-length method in apical four- and two-chamber views, immediately before mitral valve opening (Volmax ) and at mitral valve closure (Volmin ). LAD was defined as (Volmax  - Volmin ) × 100%/Volmin . LAS (mean of maximal strain from the 4-2 chamber views) was conducted using a dedicated software package. The endpoint was hospitalization for heart failure and death from any cause. RESULTS: Left atrial strain, LAD, and LA vol/m² were significantly correlated with LV diastolic parameters, and PASP (all, P < 0.05). However, LAD and LAS but not LA vol/m² were significantly correlated with Charlson score, LV global longitudinal strain, and to transaortic mean gradient (all, P < 0.05). At a median follow-up of 25 months, 53 patients had an event. LAS, LAD, LA vol/m², and Charlson index were associated with events (all, P < 0.05). In multivariate analysis, LAD, LAS, and Charlson index (all, P < 0.01) remained independently associated with events. Using a ROC curve analysis, LAD ≤ 69% and LAS ≤ 17% were the best cutoffs associated with an event. CONCLUSION: In patients with moderate to severe AS, LAD and LAS are associated with LV dysfunction, AS severity, and are independently linked to events.

Noninvasive Coronary Flow Reserve Predicts Response to Exercise in Asymptomatic Severe Aortic Stenosis.

BACKGROUND: In patients with asymptomatic aortic stenosis (AS), exercise stress echocardiography (ESE) provides additional prognostic information beyond baseline. The coronary flow velocity reserve (CFVR) is impaired in AS, but its link with exertion is unknown in this setting. The aim of this study was to test the hypothesis that CFVR could predict exercise capacity and abnormal exercise test results in AS. METHODS: Noninvasive CFVR and symptom-limited semisupine ESE were prospectively performed the same day in 43 patients with asymptomatic isolated severe AS (mean age, 68.5 ± 11 years; 26% women; mean aortic valve area, 0.8 ± 0.16 cm2; mean left ventricular ejection fraction, 70 ± 7%). CFVR was performed in the distal part of the left anterior descending coronary artery using intravenous adenosine infusion (140 µg/kg/min over 2 min), and ESE was performed at an initial workload of 25 W with a 20- to 25-W increase at 2-min intervals. An abnormal result on ESE was defined as onset of symptoms at <75% of maximum predicted workload, electrocardiographic ST-segment depression ≥2 mm during exercise, increase of systolic blood pressure < 20 mm Hg or decrease in blood pressure, and complex ventricular arrhythmia. Seventeen patients with isolated severe asymptomatic AS, unable to exercise because of extracardiac conditions, served as a comparative group. RESULTS: Resting, hyperemic left anterior descending coronary artery flow velocity and CFVR (2.45 ± 0.8 vs 2.4 ± 0.8) were similar between the group unable to perform ESE and the ESE group (P = NS for all). Compared with patients with normal results on ESE, those with abnormal results on ESE (n = 22) were older, had higher E/e' ratios, had higher resting left anterior descending coronary artery flow velocities (39 ± 12 vs 31 ± 8 cm/sec), and had lower CFVR (2.01 ± 0.3 vs 2.85 ± 0.7; P < .01 for all). Furthermore, CFVR was significantly correlated with age, changes in transvalvular pressure gradient and left ventricular ejection fraction with exercise, workload (in watts), and exercise duration (P < .05 for all). After adjusting for other variables, CFVR remained independently correlated with exercise duration, workload, and abnormal results on ESE (P < .01 for all). On receiver operating characteristic curve analysis, CFVR < 2.3 was the best cutoff to predict abnormal results on ESE (area under the curve = 0.88 ± 0.06, P < .01). CONCLUSIONS: In patients with asymptomatic severe AS, noninvasive CFVR is correlated with exercise duration and workload, and low CFVR predicts abnormal results on ESE with good accuracy.

Usefulness of two-dimensional longitudinal strain pattern to predict left ventricular recovery and in-hospital complications after acute anterior myocardial infarction treated successfully by primary angioplasty.

BACKGROUND: The aim of this study was to test the usefulness of two-dimensional longitudinal strain pattern in segments with wall motion abnormalities to predict left ventricular recovery and in-hospital cardiac events as well as coronary microvascular impairment (CMI) in patients with recent acute anterior myocardial infarction. METHODS: Forty-nine consecutive patients with acute myocardial infarction (mean age, 59 ± 13 years) treated successfully with primary coronary angioplasty prospectively underwent transthoracic Doppler echocardiography 24 hours after angioplasty and during follow-up (6 months). A two-dimensional strain analysis, including measurement of the duration of systolic lengthening expressed as a percentage of systolic duration (SL % duration), the lengthening-to-shortening ratio, the postsystolic shortening index in segments with wall motion abnormalities, and global longitudinal strain and left anterior descending coronary artery territory strain, was performed. Cardiac events were defined as a composite of death, reinfarction, and heart failure. CMI was assessed noninvasively by transthoracic Doppler left anterior descending coronary artery investigation <24 h after angioplasty and was defined as coronary flow velocity reserve < 1.7 and/or a no-reflow pattern (mean coronary flow velocity reserve, 1.8 ± 0.6 in the whole group). RESULTS: At the segmental level, SL % duration, lengthening-to-shortening ratio, and postsystolic shortening index were correlated with recovery (defined as normalization of wall motion abnormalities), whereas in multivariate analysis, only SL % duration independently predicted recovery (threshold level, 40%; area under the curve, 0.76; P < .01). At the patient level, in univariate analysis, SL % duration, global longitudinal strain, left anterior descending coronary artery territory strain, and troponin peak were correlated with recovery (defined as an absolute improvement of left ventricular ejection fraction of >5%). In multivariate analysis, SL % duration was independently related to recovery (area under the curve, 0.78; P < .01). Furthermore, SL % duration was independently linked to cardiac events (n = 13) and CMI (n = 24) (P < .01 for all). CONCLUSIONS: In patients with AMI treated by primary angioplasty, two-dimensional strain predicts left ventricular recovery independently of more traditional parameters and is independently linked to cardiac events and CMI.

Relationship between acute strain pattern and recovery in tako-tsubo cardiomyopathy and acute anterior myocardial infarction: a comparative study using two-dimensional longitudinal strain.

After acute-anterior myocardial infarction (AMI), left ventricular (LV) viable myocardial segments show some degree of active deformation (longitudinal shortening) despite wall motion abnormalities (WMA). Tako-tsubo cardiomyopathy (TTC) is characterized by myocardial stunning; however, it is unclear whether in TTC the strain pattern mimics AMI. To compare the strain-pattern in TTC and AMI using the 2D-longitudinal strain by speckle-tracking in segments with WMA, and its relationship with recovery of function at follow-up. 21 consecutive patients with typical TTC and 21 age-matched AMI patients treated by primary angioplasty had an analysis of LV-longitudinal strain at the acute-phase and at follow-up (1 and 6 months later for TTC and AMI respectively). The recovery of a segment was defined as normal wall motion at follow-up. Among the 706 analyzable LV-segments at the acute-phase, 406 had WMA (TTC 229, AMI 177). At follow-up, total recovery was observed for 45 % segments in AMI and 100 % in TTC, (p < 0.01). At the acute phase, systolic lengthening duration (47 ± 43 vs. 18 ± 33 %) and amplitude (0.25 ± 0.29 vs. 0.09 ± 0.19) and post systolic shortening (67 ± 53 vs. 39 ± 38 %) were higher in TTC, when compared to AMI-recovery (all, p < 0.01). In AMI, systolic lengthening duration was an independent predictor of poor recovery in multivariate analysis, linked to segmental longitudinal strain at follow-up (all, p ≤ 0.01). Furthermore, among the 57 % of segments exhibiting any systolic lengthening duration in AMI, only » recovered, versus 62 % of such segments in TTC with 100 % recovery (p < 0.001). The systolic passive motion which is closely and inversely linked to recovery in AMI is paradoxically frequent and severe in TTC. This suggests that myocardial stunning in TTC and AMI is different according to longitudinal strain.