Left atrial coupling index predicts heart failure and atrial fibrillation in the general population

Background It is well known that left atrial (LA) function and size can provide significant information regarding the risk of atrial fibrillation (AF) and heart failure (HF). The ratio of LA volume index and tissue doppler imaging a' (peak myocardial velocity of the left ventricle in late diastole exposing the atrial contraction) provides the LA volumetric/mechanical coupling index (LACi). LACI is a novel echocardiographic measurement which combines information of LA size and function in one measure with limited previous investigation. Purpose The aim of the present study was to investigate the prognostic value of LACi in relation to incident HF and AF in the general population. Methods The present study included 4,003 participants from a prospective general population. All participants were examined with echocardiography. Incident HF and AF were investigated as separate outcomes. Exclusion criteria were AF and/or HF at baseline. LACi was calculated as the index of LAVI (left atrial volume index) and peak tissue velocity at late diastole measured with pulsed wave Doppler at the septal base of the left ventricle. Results Mean age was 56±17 years, 57% were female, and median LACi was 2.3 [IQR: 1.8, 3.0]. The median follow-up time was 5.4 [IQR: 4.5, 6.3] years. A total of 82 and 164 developed HF and AF during follow-up, respectively. Median LACi was significantly higher among participants developing HF (2.6 [IQR: 2.1, 3.8], P<0.001) and AF (2.8 [IQR: 2.1, 4.1], P<0.001) compared to those who remained event free (2.3 [IQR: 1.8, 3.0]). Multivariable Cox proportional hazard regression models were constructed and adjusted for gender, age, smoking status, hypercholesterolemia, diabetes mellitus, ischaemic heart disease at baseline, hypertension, left ventricular ejection fraction and left ventricular diastolic function (E/e'). LACi was an independent predictor of incident HF and of AF in both univariable and multivariable Cox regression models (Figure 1). LACi remained a significant predictor of both HF and AF in a sensitivity analysis with subgroups in which LAVI was normal and enlarged, respectively (Figure 1). Conclusion LACi is an independent predictor of HF and AF in the general population. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): The Danish Heart Foundation and The Metropolitan Region of Denmark.