Noninvasive estimation of pulmonary capillary wedge pressure in patients with mitral regurgitation: A speckle tracking echocardiography study

Background: Echocardiographic parameters to predict pulmonary capillary wedge pressure (PCWP) in mitral regurgitation (MR) are not yet elucidated. We reported that PCWP could be accurately estimated by novel KT index which is defined as log₁₀[left atrial (LA) emptying function (EF)/LA volume]. We examined the usefulness of the KT index as a predictor of PCWP in primary and secondary MR with sinus rhythm and also MR with atrial fibrillation. Methods: LA dimension, strain, volume, EF, and E/ e' were measured in moderate to severe MR with sinus rhythm (n= 58, age: 67 ± 8 years) and MR with atrial fibrillation (n= 24, age: 69 ± 11 years) just before catheterization and in normal subjects (n= 26, age: 67 ± 11 years) using speckle tracking echocardiography. MR with sinus rhythm was divided into primary MR (n= 27) and secondary MR (n= 31). The estimated PCWP (ePCWP) was calculated as 10.8-12.4 × KT index. Results: There was a correlation between PCWP and LA dimension, E/ e', minimum LA volume index, active LAEF, total LAEF, or LA strain (r= 0.32, r= 0.31, r= 0.55, r= -0.61, r= -0.51, and r= -0.50, respectively, p< 0.05). The better correlation was found between PCWP and ePCWP in MR including both primary and secondary MR and also MR with atrial fibrillation (r= 0.70, r= 0.67, and r= 0.58, respectively, p< 0.01). Multiple regression analysis revealed that ePCWP was an independent predictor of PCWP in MR. The ePCWP demonstrated good diagnostic accuracy (area under the curve of 0.86) and sensitivity (81%) and specificity (71%) to predict elevated PCWP >15. mmHg using a cut-off of 16 mmHg. Conclusion: The ePCWP was the reliable echocardiographic parameter to predict PCWP in primary and secondary MR and might also be useful in MR with atrial fibrillation. The ePCWP may have an incremental value in a clinical setting.