Effects of chronic kidney disease on myocardial washout rate of thallium-201 in patients with normal myocardial perfusion on single photon emission computed tomography

Methods of calculating 123I-β-methyl-P-iodophenyl-pentadecanoic acid washout rates in triglyceride deposit cardiomyovasculopathy

OBJECTIVE

This study aimed to optimize various methods of calculating washout rates (WRs) of 123I-β-methyl-p-iodophenyl-pentadecanoic (BMIPP), as they are essential to diagnose triglyceride deposit cardiomyovasculopathy (TGCV) which is a rare disease entity identified in Japan and has been encoded in Orphanet (ORPHA code 565612).

METHODS

We calculated WRs of 123I-BMIPP from early (20 min) and delayed (200 min) images. We evaluated six methods of calculating WRs to discriminate TGVC patients (age, 56.8 ± 14.6 y; male, n = 13; female, n = 4) and 21 123I-BMIPP studies were involved including 4 follow-up studies. Washout rates were calculated by two planar methods using anterior images with cardiac and background regions of interest (ROIs) and by four SPECT methods using either array and polar plots or summed short-axis images. The final diagnoses of TGCV were confirmed according to the 2020 diagnostic criteria, and the diagnostic accuracy of WRs calculated using the six methods was analyzed using the area under receiver-operating characteristics curves (ROC-AUC). Multiple scatter-plot matrix methods were evaluated with correlations for comparison.

RESULTS

All six methods were useful for diagnosis and did not significantly differ. The four SPECT methods showed excellent diagnostic accuracy (AUC 1.0), whereas the planar methods with and without background correction could be acceptable (AUC 0.857 and 0.964, respectively). The WRs were relatively lower for patients with CAD and remarkable metabolic defects than for patients with TGCV but without defects.

CONCLUSIONS

For the diagnosis of TGCV, the WR cutoff of 10% of 123I-BMIPP functioned well in planar and SPECT discrimination based on computational methods as a classifier. However, calculation optimization should improve TGCV diagnoses.

Associations of frontal QRS-T angle with left ventricular volume and function derived from ECG-gated SPECT in patients with advanced chronic kidney disease

BACKGROUND

The frontal QRS-T angle is one of markers of ventricular repolarization. We investigated whether or not the frontal QRS-T angle could predict left ventricular (LV) volume and function derived from ECG-gated SPECT in patients with advanced chronic kidney disease (CKD).

METHODS

Two hundred and twelve patients with advanced CKD defined as estimated glomerular filtration rate of < 45 ml min-1/1.73 m2 were enrolled. Wide QRS-T angle was defined as its angle of > 90°, and was considered abnormal. Enlarged LV end-diastolic volume (LVEDV) was defined as LVEDV index of > 76 ml m-2 in men and > 57 ml m-2 in women. Reduced LV ejection fraction (LVEF) was defined as LVEF of < 40%.

RESULTS

Fifty-one patients (24%) had wide QRS-T angle, and 161 patients (76%) had normal QRS-T angle. Patients with wide QRS-T angle had larger SSS [9 (5-16) vs 4 (1-9), p < 0.001], larger LVEDV index (69 ± 29 vs 50 ± 18 ml m-2, p < 0.001) and lower LVEF (47 ± 13 vs 59 ± 12%, p < 0.001) than those with normal QRS-T angle. Multivariate analysis showed that wide QRS-T angle (odds ratio 5.93; 95% CI 2.55-14.33; p < 0.001) was significantly associated with enlarged LVEDV, whereas SSS severity was not. Severely abnormal SSS (odds ratio 3.80; 95% CI 1.16-14.05; p < 0.03) and wide QRS-T angle (odds ratio 5.67; 95% CI 2.10-16.22; p < 0.001) were significantly associated with reduced LVEF.

CONCLUSIONS

Our results suggest that wide QRS-T angle is associated with LV remodeling such as enlarged LVEDV or reduced LVEF in patients with advanced CKD.

Hybrid Blood Purification Therapy Based on Camel Nanoantibody Immunoadsorbent on Patients with Chronic Renal Failure in Nephrology Department

This paper proposes a study on the effect of hybrid blood purification therapy based on camel nanoantibody immunoadsorbent on chronic renal failure patients in nephrology department. In this paper, the hybrid blood purification therapy based on camel nanoantibody immunoadsorbent was applied to patients with chronic renal failure, and the curative effect of the patients was studied. In order to highlight the effect, a control group was set up for comparison. In this paper, the clearance effect of small molecule toxin, middle molecular toxin, and dialysis adequacy was analyzed. This study found that the average dialysis adequacy of the control group was 1.23% and that of the experimental group was 1.26%. The dialysis adequacy of the experimental group was significantly better than that of the control group. In addition, the clearance effect of small and medium molecular toxins in the experimental group was significantly better than that in the control group. It can be seen that the hybrid blood purification therapy based on camel nanoantibody immunoadsorbent is effective in the treatment of chronic renal failure patients in the department of nephrology. Therefore, it is of great value to apply camel nanoantibody in the clinical treatment of renal failure.

Implications of electrocardiographic frontal QRS axis on left ventricular diastolic parameters derived from electrocardiogram-gated myocardial perfusion single photon emission computed tomography

BACKGROUND

Current electrocardiographic (ECG) machines report various variables including frontal QRS axis automatically. We tested the hypothesis that QRS axis is associated with left ventricular (LV) diastolic parameters derived from ECG-gated myocardial perfusion single photon emission computed tomography (SPECT) independent of myocardial ischemia.

METHODS

Ninety-three patients with preserved LV ejection fraction and no evidence of myocardial ischemia were enrolled based on ECG-gated SPECT. Peak filling rate (PFR), one-third mean filling rate (1/3 MFR) and time to peak filling (TTPF) were obtained as LV diastolic parameters.

RESULTS

There were 82 male and 11 female patients with a mean age of 69 ± 9 years. QRS axis ranged from - 40° to 85° (36° ± 31°). QRS axis was correlated with PFR (r = 0.28, p < 0.01), 1/3 MFR (r = 0.25, p = 0.02) and TTPF (r = - 0.21, p = 0.04). QRS axis was also correlated with age (r = - 0.23, p = 0.03), body mass index (BMI) (r = - 0.36, p < 0.01) and LV mass index (LVMI) (r = - 0.27, p < 0.01). Linear regression analysis showed that QRS axis was associated with PFR, 1/3 MFR and TTPF for LV diastolic function, but was not associated with these LV diastolic parameters after adjustment of various confounders.

CONCLUSIONS

Our data suggest that QRS axis depends on age, BMI or LVMI, and serves as a surrogate marker of LV diastolic function.