Impact of Left Atrial Phasic Function in Heart Failure With Preserved Ejection Fraction

Right Atrial Phasic Function in Heart Failure with Preserved Ejection Fraction: Cardiac Magnetic Resonance Feature Tracking and Outcomes

BACKGROUND

This study sought to investigate the prognostic impact of right atrial (RA) size and function in patients with heart failure with preserved ejection fraction (HFpEF) in sinus rhythm (SR) and atrial fibrillation (AF).

METHODS

Consecutive HFpEF patients were enrolled and indexed RA volumes and emptying fractions (RA-EF) were assessed by cardiac magnetic resonance imaging (CMR). For patients in SR, feature tracking of the RA wall was performed during CMR. In addition, all patients underwent right and left heart catheterization and 6 min walk distance (6MWD) and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) evaluations. We prospectively followed patients and used Cox regression models to determine the association of RA size and function with a composite endpoint of heart failure hospitalization and cardiovascular death.

RESULTS

A total of 188 patients (71% female patients, 70 ± 8 years old) were included. Ninety-two patients (49%) were in persistent AF. Eighty-five patients reached the combined endpoint during a follow-up of 69 (42-97) months. After a multivariate cox regression analysis, the impaired RA reservoir strain (HR 0.949; 95% CI [0.909-0.990], p = 0.016), the RA reservoir strain rate (HR 0.991; 95% CI [0.983-0.999], p = 0.028), the RA conduit strain (HR 0.932; 95% CI [0.879-0.988], p = 0.019), and the RA conduit strain rate (HR 0.989; 95% CI [0.881-0.997], p = 0.011) were significantly associated with a worse outcome for patients in SR. In persistent AF, no RA imaging parameter was related to outcome after a multivariate regression analysis.

CONCLUSIONS

In HFpEF patients in SR, CMR parameters of impaired RA conduit and reservoir function are associated with dismal cardiovascular outcomes. In persistent AF, RA parameters lose their prognostic ability.

State-of-the-art myocardial strain by CMR feature tracking: clinical applications and future perspectives

Based on conventional cine sequences of cardiac magnetic resonance (CMR), feature tracking (FT) is an emerging tissue tracking technique that evaluates myocardial motion and deformation quantitatively by strain, strain rate, torsion, and dyssynchrony. It has been widely accepted in modern literature that strain analysis can offer incremental information in addition to classic global and segmental functional analysis. Furthermore, CMR-FT facilitates measurement of all cardiac chambers, including the relatively thin-walled atria and the right ventricle, which has been a difficult measurement to obtain with the reference standard technique of myocardial tagging. CMR-FT objectively quantifies cardiovascular impairment and characterizes myocardial function in a novel way through direct assessment of myocardial fiber deformation. The purpose of this review is to discuss the current status of clinical applications of myocardial strain by CMR-FT in a variety of cardiovascular diseases. KEY POINTS: • CMR-FT is of great value for differential diagnosis and provides incremental value for evaluating the progression and severity of diseases. • CMR-FT guides the early diagnosis of various cardiovascular diseases and provides the possibility for the early detection of myocardial impairment and additional information regarding subclinical cardiac abnormalities. • Direct assessment of myocardial fiber deformation using CMR-FT has the potential to provide prognostic information incremental to common clinical and CMR risk factors.

Prognostic impact of left atrial function in heart failure with preserved ejection fraction in sinus rhythm vs. persistent atrial fibrillation

Aims

We sought to determine the prognostic impact of left atrial (LA) size and function in patients with heart failure with preserved ejection fraction (HFpEF) in sinus rhythm (SR) vs. atrial fibrillation (AF).

Methods and results

We enrolled consecutive HFpEF patients and assessed indexed LA volumes and emptying fractions (LA‐EF) on cardiac magnetic resonance imaging. In addition, all patients underwent right and left heart catheterization, 6 min walk test, and N‐terminal prohormone of brain natriuretic peptide evaluation. We prospectively followed patients and used Cox regression models to determine the association of LA size and function with a composite endpoint of heart failure hospitalization and cardiovascular death. A total of 188 patients (71% female patients, 70 ± 8 years old) were included of whom 92 (49%) were in persistent AF. Sixty‐five patients reached the combined endpoint during a follow‐up of 31 (9–57) months. Multivariate Cox regression adjusted for established risk factors revealed that LA‐EF was significantly associated with outcome in patients in SR [adjusted hazard ratio 2.14; 95% confidence interval (1.32–3.47) per 1‐SD decline, P = 0.002]. In persistent AF, no LA imaging parameter was related to outcome. By receiver operating characteristic and restricted cubic spline analyses, we identified an LA‐EF ≥ 40% as best indicator for favourable outcomes in patients with HFpEF and SR. Persistent AF carried a similar risk for adverse outcome compared with impaired LA‐EF (<40%) in SR (log‐rank, P = 0.340).

Conclusions

In HFpEF patients in SR, impaired LA‐EF is independently associated with worse cardiovascular outcome, which is similar to persistent AF. In persistent AF, LA parameters lose their prognostic ability.

Left atrial phasic transport function closely correlates with fibrotic and arrhythmogenic atrial tissue degeneration in atrial fibrillation patients: cardiac magnetic resonance feature tracking and voltage mapping

AIMS

To characterize the association of phasic left atrial (LA) transport function and LA fibrosis guided by multimodality imaging containing cardiac magnetic resonance imaging (CMR) feature tracking and bipolar voltage mapping.

METHODS AND RESULTS

Consecutive patients presenting for first-time ablation of atrial fibrillation (AF) were prospectively enrolled. Each patient underwent CMR prior to the ablation procedure. LA phasic indexed volumes (LA-Vi) and emptying fractions (LA-EF) were calculated and CMR feature tracking guided LA wall motion analysis was performed. LA bipolar voltage mapping was carried out in sinus rhythm to find areas of low voltage as a surrogate for fibrosis and arrhythmogenesis. One hundred and sixty-eight patients were enrolled. Low-voltage areas (LVAs) were present in 70 patients (42%). Contrary to LA volume, CMR based LA-EF [odds ratio (OR) 0.88, 95% confidence interval (CI) 0.80-0.96, P = 0.005] and LA booster pump strain rate (SR) (OR 0.98, 95% CI 0.97-0.99, P = 0.001) significantly predicted presence and extent of LVA in multivariate logistic regression analysis for patients scanned in SR. In receiver operating characteristic analysis, LA-EF <40% carried a sensitivity of 83% and specificity of 76% (area under the curve 0.8; 95% CI 0.71-0.89) to predict presence of LVA. For patients scanned in AF only minimal LA-Vi on CMR (OR: 1.06; 95% CI: 1.02-1.10; P = 0.002) predicted presence of LVA.

CONCLUSION

For patients scanned in SR LA-EF and LA booster pump SR are closely linked to the presence and extent of LA LVA.