The left ventricular (LV) remodeling process associated with significant valvular heart disease (VHD) is characterized by an increase of myocardial interstitial space with deposition of collagen and loss of myofibers. These changes occur before LV systolic function deteriorates or the patient develops symptoms. Cardiovascular magnetic resonance (CMR) permits assessment of reactive fibrosis, with the use of T1 mapping techniques, and replacement fibrosis, with the use of late gadolinium contrast enhancement. In addition, functional consequences of these structural changes can be evaluated with myocardial tagging and feature tracking CMR, which assess the active deformation (strain) of the LV myocardium. Several studies have demonstrated that CMR techniques may be more sensitive than the conventional measures (LV ejection fraction or LV dimensions) to detect these structural and functional changes in patients with severe left-sided VHD and have shown that myocardial fibrosis may not be reversible after valve surgery. More important, the presence of myocardial fibrosis has been associated with lesser improvement in clinical symptoms and recovery of LV systolic function. Whether assessment of myocardial fibrosis may better select the patients with severe left-sided VHD who may benefit from surgery in terms of LV function and clinical symptoms improvement needs to be demonstrated in prospective studies. The present review article summarizes the current status of CMR techniques to assess myocardial fibrosis and appraises the current evidence on the use of these techniques for risk stratification of patients with severe aortic stenosis or regurgitation and mitral regurgitation.

Aims: To evaluate standard reporting of cardiac chambers size and function by transthoracic echocardiography (TTE), the EACVI Scientific Initiatives Committee performed a survey across European centres. In particular, the routine use of three-dimensional echocardiography (3DE) and speckle tracking-derived myocardial deformation imaging (STE) was explored. Methods and results: A total of 96 European Echocardiography Laboratories from 22 different countries responded to the survey, which consisted of 20 questions. For most of the standard parameters of cardiac chamber size and function, answers from the centres were homogeneous and demonstrated good adherence to current recommendations. In particular, all centres assessed left ventricular (LV) and left atrial (LA) size combining diameter measurements with volumes obtained using the bi-plane Simpson’s method. More variability was observed in the measurements of the right heart chambers and thoracic aorta. Interestingly, >90% of centres had access to 3DE and STE; however, the large majority of centres reserved the use of these techniques for selected cases, particularly for the measure of 3D LV volumes and ejection fraction and global longitudinal strain in patients being considered for cardiac device implantation, surgical intervention (valvular heart disease) or screened for cardiotoxicity. Only 10% of centres used 3DE for right ventricular and LA volumes. Also, <30% of the centres used LA strain imaging. Conclusion: In Europe, a good adherence to current recommendations was observed for most of the standard parameters of cardiac chambers quantification by TTE. Advanced echocardiography modalities, such as 3DE and STE, are widely available but used only in selected cases.

In patients with atrial fibrillation (AF), left atrial (LA) fibrosis is a major determinant of the progression to, and burden of AF. LA reservoir strain and total atrial conduction time (PA-TDI) reflect LA fibrotic content. We aimed to investigate the relation between LA reservoir strain and PA-TDI in AF patients and control subjects. Six-hundred two patients (mean age 56 years, 53% men) with first episode of AF and 342 controls (mean age 64 years, 71% men) without structural heart disease underwent echocardiography. LA volumes, PA-TDI, LA reservoir strain, and left ventricular global longitudinal strain (GLS) were compared. Compared with controls, patients with paroxysmal AF and patients with persistent AF had longer PA-TDI (128 ± 25 millisecond, 140 ± 31 millisecond, and 154 ± 33 millisecond, respectively; p <0.001) and a progressive decline in LA reservoir strain (36.9 ± 11.6%, 29.8 ± 13.4%, 24.2 ± 12.3%, respectively; p <0.001). LA reservoir strain was negatively correlated with PA-TDI (r = -0.43, p <0.001). On multivariate analyses, LA reservoir strain, diabetes mellitus, and burden of AF were independent correlates of PA-TDI (R2 = 0.23, p <0.001); whereas only PA-TDI was an independent correlate of LA reservoir strain (R2 = 0.43, p <0.001); controlling for age, hypertension, coronary artery disease, body mass index, severity of mitral regurgitation, left ventricular global longitudinal strain, and LA volume. In conclusion, PA-TDI and LA reservoir strain are negatively correlated in all subjects, irrespective of the presence or burden of AF. Patients with persistent AF have longer PA-TDI and impaired LA reservoir strain compared with paroxysmal AF and controls, suggesting increasing burden of fibrosis and LA structural remodeling in the progression of AF.

Aging is associated with changes in left atrial (LA) structure and function. The present study aimed at describing the effect of aging on LA properties in a large cohort of subjects without structural heart disease. We divided 386 subjects (mean age 58 years [range 16 to 91]; 188 men [49%]) clinically referred for echocardiography according to age groups. The P-wave dispersion (PWD), reflecting total atrial conduction time, was measured on a 12-lead surface electrocardiogram as the difference between maximum and minimum P-wave duration. The PA-TDI duration reflecting the total atrial conduction time was measured on tissue Doppler imaging (TDI) as the time between onset of P wave on surface electrocardiogram to peak A'-wave velocity. Two-dimensional speckle-tracking echocardiography was used to assess LA reservoir function, reflecting LA compliance. In the overall population, mean PWD, PA-TDI, and LA reservoir strain were 43 ± 12 ms, 129 ± 27 ms, and 36 ± 13%, respectively. Increasing age was independently associated with prolonged PWD (β = 0.161; p <0.001), PA-TDI (β = 0.476; p <0.001), and reduced LA reservoir strain (β = -0.259; <0.001), suggesting age-related fibrotic changes of the LA myocardium. The association between age and LA reservoir strain was modulated by body mass index (β = -0.582; p <0.001) and LA volume index (β = -0.117; p = 0.014). In conclusion, aging is associated with longer PWD and PA-TDI duration along with a decrease in LA reservoir function. Obesity and larger LA volumes are independently associated with reduced LA compliance.

We aimed to evaluate the effect of early intravenous metoprolol treatment, microvascular obstruction (MVO), intramyocardial hemorrhage (IMH) and adverse left ventricular (LV) remodeling on the evolution of infarct and remote zone circumferential strain after acute anterior ST-segment elevation myocardial infarction (STEMI) with feature-tracking cardiovascular magnetic resonance (CMR). A total of 191 patients with acute anterior STEMI enrolled in the METOCARD-CNIC randomized clinical trial were evaluated. LV infarct zone and remote zone circumferential strain were measured with feature-tracking CMR at 1 week and 6 months after STEMI. In the overall population, the infarct zone circumferential strain significantly improved from 1 week to 6 months after STEMI (− 8.6 ± 9.0% to − 14.5 ± 8.0%; P < 0.001), while no changes in the remote zone strain were observed (− 19.5 ± 5.9% to − 19.2 ± 3.9%; P = 0.466). Patients who received early intravenous metoprolol had significantly more preserved infarct zone circumferential strain compared to the controls at 1 week (P = 0.038) and at 6 months (P = 0.033) after STEMI, while no differences in remote zone strain were observed. The infarct zone circumferential strain was significantly impaired in patients with MVO and IMH compared to those without (P < 0.001 at 1 week and 6 months), however it improved between both time points regardless of the presence of MVO or IMH (P < 0.001). In patients who developed adverse LV remodeling (defined as ≥ 20% increase in LV end-diastolic volume) remote zone circumferential strain worsened between 1 week and 6 months after STEMI (P = 0.036), while in the absence of adverse LV remodeling no significant changes in remote zone strain were observed. Regional LV circumferential strain with feature-tracking CMR allowed comprehensive evaluation of the sequelae of an acute STEMI treated with primary percutaneous coronary intervention and demonstrated long-lasting cardioprotective effects of early intravenous metoprolol. ClinicalTrials.gov, NCT01311700. Registered 8 March 2011 - Retrospectively registered.