Pre- and Post-Transcatheter Aortic Valve Replacement Serum Brain Natriuretic Peptide Levels and All-Cause Mortality

BACKGROUND

Risk stratification in patients post-transcatheter aortic valve replacement (TAVR) is limited to and is based on clinical judgment and surgical scoring systems. Serum natriuretic peptides are used for general risk stratification in patients with aortic stenosis, reflecting the increase in their afterload and thereby stressing the need for valve intervention. The objective of this study was to determine the predictive value of pre- and post-procedural serum brain natriuretic peptide (BNP) on 1-year all-cause mortality in patients who underwent TAVR.

METHODS

In this population-based study, we included 148 TAVR patients treated at the Poriya Medical Center between June 1, 2015, and May 31, 2018. Routine blood samples for serum BNP levels (pg/mL) were taken just before the TAVR and 24 h post-TAVR. Our primary clinical outcome was defined as 1-year all-cause mortality. We used backward regression models and included all variables that had a p value <0.1 in the univariable analysis. A receiver-operating characteristic curve was calculated for the prediction of all-cause mortality by serum BNP levels using the median as the cut-off point.

RESULTS

In this study cohort, BNP levels 24 h post-TAVR higher than the cohort median versus lower than the cohort median (387.5 pg/mL; IQR 195-817.6) were the strongest predictor of 1-year mortality (hazard ratio 9; 95% CI 2.72-30.16; p < 0.001). The statistically significant relationship was seen in the unadjusted regression model as well as after the adjustment for clinical variables.

CONCLUSIONS

Serum BNP levels 24 h post-procedure were found to be a meaningful marker in predicting 1-year all-cause mortality in patients after TAVR procedure.

Does the aortic annulus undergo conformational change throughout the cardiac cycle? A systematic review

Accurate annular sizing in transcatheter aortic valve implantation (TAVI) planning is essential. It is now widely recognized that the annulus is an oval structure in most patients, but it remains unclear if the annulus undergoes change in size and shape during the cardiac cycle that may impact prosthesis size selection. Our aim was to assess whether the aortic annulus undergoes dynamic conformational change during the cardiac cycle and to evaluate possible implications for prosthesis size selection. We performed a systematic search in PubMed and Embase databases and reviewed all available literature on aortic annulus measurements in at least two cardiac phases. Twenty-nine articles published from 2001 to 2014 were included. In total, 2021 subjects with and without aortic stenosis were evaluated with a mean age ranging from 11 ± 3.6 to 84.9 ± 7.2 years. Two- and three-dimensional echocardiography was performed in six studies each, magnetic resonance imaging was used in one and computed tomography in 17 studies. In general, the aortic annulus was more circular in systole and predominantly oval in diastole. Whereas the annular long-axis diameter showed insignificant change throughout the cycle, the short-axis diameter, area, and perimeter were significantly larger in systole compared with diastole. Hence, the aortic annulus does undergo dynamic changes during the cardiac cycle. In patients with large conformational changes, diastolic compared with systolic measurements can result in undersizing TAVI prostheses. Due to the complex annular anatomy and dynamic change, three-dimensional assessment in multiple phases has utmost importance in TAVI planning to improve prosthesis sizing.