P176 Left ventricular diastolic function by gated myocardial perfusion SPECT strongly reflects NT-ProBNP

Background

The importance of left ventricle diastolic dysfunction (LVDD) has been recognized widely, as it is well established that heart failure with preserved ejection fraction has a poor prognosis. Furthermore, N-terminal pro–B-type natriuretic peptide (NT-ProBNP) is used as a marker of heart failure. However, the association between LVDD and NT-proBNP is unclear. 

Purpose

The aim of this study was to clarify the association between LVDD and NT-ProBNP. 

Methods

In this study, an index based on gated myocardial perfusion SPECT using CardioREPO software for the diagnosis of LVDD was used. Out of the 171 patients who underwent myocardial perfusion imaging (MPI) between January 2015 and December 2018, 163 individuals (116 men and 47 women) completed MPI and NT-ProBNP. Patients were classified into 4 groups: NT-ProBNP levels below 125 pg/ml (n = 52), NT-ProBNP levels 125 to 400 pg/ml (n = 33), NT-ProBNP levels 400 to 900 pg/ml (n = 23), and NT-ProBNP levels over 900 pg/ml (n = 37). CardioREPO parameters (peak filling rate　(PFR), 1/3 mean filling rate (MFR), and time to peak filling rate/R-R (TTPFR)) were compared between the 4 NT-ProBNP groups. 

Results

Of the 163 patients, 55 had LVDD. The PFR and 1/3MFR were associated with LVDD. There was a statistically significant difference in PFR and 1/3 MFR between the NT-ProBNP levels below 125 pg/ml group and the NT-ProBNP levels 400 to 900 pg/ml group (PFR = 2.51+/-1.11 vs. 1.80+/-0.65, p = 0.001; 1/3 MFR = 1.41+/-0.55 vs. 1.06+/-0.47, p = 0.006, Table).

Conclusions

The MPI indices obtained by CardioREPO software were useful in the diagnosis of LVDD. The evaluation of LVDD by MPI correlated with NT-Pro BNP level is thought to have a clinical utility in the diagnosis and management of LVDD.

Variable: NT-ProBNP 　 0-125 (n = 52) 125-400 (n = 33) 400-900 (n = 23) 900- (n = 37) p Age 66 ± 11 72 ± 11 68 ± 17 70 ± 12 0.133 Male 40 (77%) 22 (12%) 18 (78%) 23 (62%) 0.36 Left ventricular diastolic dysfunction 8 (15%) 4 (12%) 10 (43%) 27 (73%) <0.001 E/A 0.9 ± 0.3 0.8 ± 0.2 1.1 ± 0.7 1.4 ± 0.9 (35) <0.001 E/e" 10.27 ± 3.69 (20) 8.83 ± 3.56 (10) 12.46 ± 3.75 (12) 20.25 ± 8.30 (25) <0.001 rest-PFR /s 2.51 ± 1.11 2.06 ± 0.58 2.16 ± 0.65 1.80 ± 0.65 0.001 rest-1/3 MFR /s 1.41 ± 0.55 1.19 ± 0.41 1.16 ± 0.50 1.06 ±0.47 0.008 rest-TTPFR ms 177 ± 53 181 ± 69 198 ± 80 166 ± 85 0.38 rest-TTPFR / R-R 　 0.19 ± 0.06 0.20 ± 0.11 0.21 ±0.09 0.21 ± 0.15 0.92

Noninvasive assessment of right heart function by 81mKr equilibrium radionuclide ventriculography in chronic pulmonary diseases

Noninvasive multigated equilibrium radionuclide ventriculography with krypton-81m (81mKr) was used to assess right heart relaxation in patients with chronic pulmonary diseases (CPD). The subjects consisted of 30 patients with CPD and 8 patients free of cardiopulmonary diseases admitted to our department. A region of interest (ROI) was selected on both the right atrium (RA) and right ventricle (RV). A time activity curve was obtained for each ROI. As a diastolic index of the right heart performance, the right atrial early emptying rate (RAER) was obtained from the right atrial time activity curve, while the right ventricular rapid filling rate (RVRFR) was obtained from the right ventricular time activity curve. The mean RAER was significantly lower in CPD patients compared with the control (CPD, 9.5 +/- 4.5; control, 16 +/- 3.4%/100 ms). Similarly, the mean RVRFR was significantly lower in CPD patients compared with the control (CPD, 27.3 +/- 9.9; control, 34 +/- 8.5%/100 ms). A strong negative correlation was noted between the mean pulmonary arterial pressure (mPAP) and RAER (r = -0.77; p < 0.001) and between the mPAP and the RVRFR (r = -0.63; p < 0.001). Our results suggest that RAER and RVRFR measured by 81mKr are clinically useful in the noninvasive assessment of right heart relaxation in patients with CPD.