*2.5. Quality Assessment*

The assessment of risk of bias and applicability concerns in the included studies was evaluated by the same investigators by using the quality assessment of diagnostic accuracy studies questionnaire (QUADAS-2), which was optimized for these study questions (Table S1: Supplement 1) [12]. The QUADAS-2 tool has 4 domains for risk of bias-patient selection, index test, reference test, and flow and timing-and three domains for applicability-patient selection, index, and reference test domains.

## *2.6. Statistical Analysis*

The meta-analysis was conducted with statistical analysis that was performed with the RevMan software (Review Manager Version 5.1, The Cochrane Collaboration, Copenhagen, Denmark), with two-tailed *p* < 0.05 considered as significant. Weighted mean differences (WMD) and a 95% confidence interval (CI) were calculated for each study. The baseline characteristics are reported as the median and range. Mean and standard deviation (SD) values were estimated by using the method described by Hozo et al. [13].

To test the potential associations between LA function and CRT response, we used the MedCalc program (Version 19.0, Medcalc Sotware, Ostend, Belgium) and applied the Hedges–Olkin (1985) method for calculating the weighted summary correlation coefficient under the fixed/random effects model by using a fisher Z transformation of the correlation coefficients. The heterogeneity statistics were incorporated to calculate the summary correlation coefficient under the random effects model (DerSimonian and Laird, 1986).

The meta-analysis is presented in forest plots and was performed with a fixed-effects model. The heterogeneity between studies was assessed with Cochran's Q test and the *I* <sup>2</sup> index. As a guide, *I* <sup>2</sup> < 25% indicated a low heterogeneity, 25–50% indicated a moderate heterogeneity, and >50% a indicated high heterogeneity [14]. To assess the additive (between-study) component of variance, the reduced maximum likelihood method (*tau*2) incorporated the occurrence of residual heterogeneity into the analysis [15]. Publication bias was assessed via visual inspections of funnel plots and Egger's test.

#### **3. Results**

#### *3.1. Search Results and Trial Flow*

Of 2819 articles identified in the initial search, 201 were screened as potentially relevant. After excluding 201 studies, 20 full articles were assessed according to the inclusion and exclusion criteria. After careful assessment of these 20 articles, 13 were excluded, and only seven articles were included in the final analysis [16–22] (Figure S1: Supplement 2). In all LA function studies, two dimensional (2D)

LA strain (PALS) was measured based on R–R gating, and the sonographers were blinded to pressure measurements. (Table S2: Supplement 3).
