Inverse correlation between age of onset and myocardial amyloid deposition quantified by 99mTc-PYP scintigraphy in patients with wild-type transthyretin amyloid cardiomyopathy.

OBJECTIVE: Wild-type transthyretin amyloidosis cardiomyopathy (ATTRwt-CM) is increasingly recognized as a contributing factor to cardiac insufficiency in the elderly population. We aimed to identify the factors affecting age of onset of ATTRwt-CM, encompassing the assessment of amyloid deposition in myocardial tissue through the use of 99mTc-pyrophosphate (PYP) and clinical parameters. METHODS: A retrospective investigation involving a consecutive cohort of 107 cases, each having been diagnosed with ATTRwt-CM confirmed through histopathological and genetic analysis, was performed. All patients underwent PYP scintigraphy, and the heart-to-contralateral (H/CL) ratio was calculated to measure amyloid deposition in the myocardium. Univariate and multivariate analyses were performed to identify independent predictors of the age of onset of ATTRwt-CM, considering the H/CL ratio and various clinical risk factors for heart failure. RESULTS: Gender (p = 0.03), Creatinine (Cr) (r = 0.32, p < 0.01), hemoglobin (Hb) (r = - 0.44, p < 0.01), albumin (Alb) (r = - 0.32, p < 0.01), brain natriuretic peptide (BNP) (r = 0.21, p = 0.03), low-density lipoprotein-cholesterol (LDL-C) (r = - 0.27, p < 0.01), and H/CL ratio (r = - 0.44, p < 0.01) were all significantly associated with the onset age. In multiple regression analysis, the independent predictive factors for the onset age of ATTRwt-CM were identified as the H/CL ratio (p < 0.01), Hb (p < 0.01), and Cr (p < 0.01). CONCLUSION: The H/CL ratio, Hb, and Cr independently affect age of onset in patients with ATTRwt-CM. The H/CL ratio is inversely correlated with age of onset, and may be the sole factor in the development of heart failure in early onset patients, while it may have a synergistic effect on heart failure with anemia and renal dysfunction in late-onset patients.

Usefulness of quantitative 99mTc-pyrophosphate SPECT/CT for predicting the prognosis of patients with wild-type transthyretin cardiac amyloidosis.

PURPOSE: Wild-type transthyretin-related amyloidosis cardiomyopathy (ATTRwt-CM) is an increasingly recognized cause of heart failure especially in elderly patients. The purpose of the present study was to determine retrospectively whether the quantitative indices of 99mTc-pyrophosphate (PYP) SPECT/CT help to predict the prognosis of ATTRwt-CM patients when compared with other clinical parameters. MATERIALS AND METHODS: Sixty-eight patients with biopsy-proven ATTRwt-CM who underwent PYP SPECT/CT were enrolled. Baseline clinical characteristics, echocardiographic parameters, and qualitative and/or quantitative indices of planar and SPECT/CT imaging in PYP scintigraphy for each patient were included. For quantitative analysis of SPECT/CT, the accumulation ratio of PYP in the septum, posterior, anterior, lateral, and apex walls to the cavity pool was calculated as the septal wall-to-cavity ratio (Se/C), lateral wall-to-cavity ratio (La/C), anterior wall-to-cavity ratio (An/C), inferior wall-to-cavity ratio (In/C), and apical wall-to-cavity ratio (Ap/C), respectively. Endpoints for prognostic accuracy evaluation were cardiac death or hospitalization due to heart failure. Event-free survival rate was evaluated through Cox proportional hazards regression analysis, providing estimated hazard ratios (HRs) with 95% confidence intervals (CIs) and Kaplan-Meier curves. RESULTS: High-sensitivity cardiac troponin T (hs-cTnT), La/C, age, interventricular septal thickness in diastole, and E/e' ratio in the septal wall were significantly associated with event-free survival (P < 0.05). For a multivariable Cox proportional hazards analysis, hs-cTnT (HR 1.153; 95% CI 1.034-1.286; P < 0.01), La/C (HR 2.091; 95% CI 1.012-4.322; P = 0.046), and age (HR 1.116; 95% CI 1.007-1.238; P = 0.037) were significant independent prognostic factors. CONCLUSION: This study indicated that the quantitative indices of PYP SPECT/CT can help to predict the prognosis of ATTRwt-CM patients.

Helicobacter pylori Eradication Using Laser Endoscope and Methylene Blue.

BACKGROUND AND AIMS: Helicobacter pylori (H. pylori) eradication has become increasingly unsuccessful due to the prevalence of antibiotic resistance. To address this global issue, a novel strategy for eradication without antibiotics must be developed. The purpose of this study was to examine the effect of methylene blue (MB) with sodium bicarbonate (NaHCO3) on H. pylori using photodynamic antimicrobial chemotherapy. MATERIALS AND METHODS: MB was basified using NaHCO3. The basic effect of MB with NaHCO3 was examined using an endoscope equipped with a laser light source. H. pylori was smeared on the culture media with basic MB, followed by illumination at approximately 1,100 lux for 10 and 20 seconds.After 4 days of culture, the basic effects were determined according to the bacterial growth. RESULTS: The basic effects of MB appeared at a pH from 8.6 to 9.0 and at NaHCO3 concentrations between 2% and 6.5%. MB concentrations of > 0.05% exhibited the basic effects. The duration of irradiation had no remarkable effects. CONCLUSIONS: Our results showed that the laser endoscope and basic MB were effective for H. pylori eradication.

Clinical usefulness of quantification of myocardial blood flow and flow reserve using CZT-SPECT for detecting coronary artery disease in patients with normal stress perfusion imaging.

BACKGROUND: Relative myocardial perfusion imaging can misdiagnose "balanced" ischemia caused by coronary artery disease (CAD). We assessed the feasibility of myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) using dynamic single-photon emission computed tomography (SPECT) with a cadmium-zinc-telluride (CZT) camera for estimating underlying CAD in patients with normal stress myocardial perfusion SPECT (MPS). METHODS: 125 patients with normal stress MPS (summed stress score ≤3) were enrolled. All patients underwent coronary angiography (CAG) and stress/rest 201Tl dynamic SPECT for MBF and MPR calculation. The diagnostic accuracy of both these quantitative values and other clinical risk factors for predicting occult CAD were validated by CAG. RESULTS: MPR was 2.85 in patients with no CAD, 2.47 with 1-, 1.98 with 2-, and 1.76 with 3-vessel CAD. The patient's age, morbidity of diabetes mellitus (DM), chronic kidney disease (CKD), stress MBF, and MPR were significantly associated with the presence of CAD (age, p=0.02; DM, p=0.005; CKD, p=0.005; creatinine level, p= 0.012, stress MBF, p=0.019, and MPR, p<0.001). Independent predictors in the multivariate regression analysis were as follows: DM, p=0.011, CKD, p=0.028, and MPR, p<0.001. The combined index was calculated from three independent predictors. Area under the receiver operating characteristic curve was 0.75 for MPR and 0.81 for the combined index. To identify CAD, sensitivity, and specificity for MPR were 77% and 66%, and for the combined index they were 79% and 66%, respectively. CONCLUSION: Quantification of MPR and MBF using dynamic SPECT with a CZT camera can be useful to identify balanced ischemia caused by occult CAD in patients with normal stress MPS findings.

Escherichia coli Sterilization Using a Light-Emitting Diode and Methylene Blue.

BACKGROUND AND AIMS: The prevalence of pathogenic Escherichia coli as well as E. coli O157 and antibiotic- resistant bacteria has increased. This study aimed to examine the effect of methylene blue (MB) with sodium bicarbonate (NaHCO3) against E. coli using photodynamic antimicrobial chemotherapy (PACT). MATERIALS AND METHODS: MB was basified using NaHCO3. E. coli and basic MB were smeared on the culture media followed by irradiation using a red light-emitting diode (LED) at 660 nm. Energy densities of 5, 10, 15, and 20 J/cm2 were applied to the culture medium.After 24 h, the bactericidal effect of basic MB with LED irradiation was determined based on the bacterial growth. RESULTS: The basic effect was observed with 1%-6% of NaHCO3 at 5 J/cm2.This effect increased between 1% and 2% of NaHCO3 at 10 J/cm2 and 15 J/cm2, whereas decreased at the NaHCO3 concentrations of > 2%. Moreover, this effect decreased at an energy density of 20 J/cm2. The biphasic basic effect on bactericidal activity was observed between pH 8.6-9.0. CONCLUSIONS: Thus, PACT using basic MB may be an effective method for pathogenic E. coli sterilization.

Helicobacter pylori Eradication Using a Light-Emitting Diode and Methylene Blue.

BACKGROUND AND AIMS: Eradication failures are increasing with the increasing antibiotic resistance of Helicobacter pylori.We examined the basic effect of methylene blue (MB) with sodium bicarbonate (NaHCO3) on H. pylori eradication using antimicrobial chemotherapy activated by light. MATERIAL AND METHODS: When NaHCO3 was added to MB, the pH became basic. We smeared H. pylori on a medium with basic MB and irradiated it using a red light-emitting diode with a wavelength of 660 nm. The applied energy fluencies were 10 J/cm2 and 15 J/cm2. After 4 days of culture, the effect of this intervention was determined according to the bacterial growth area. RESULTS: The basic effect of MB appeared between a pH of 8.6 and 9.0. The NaHCO3 concentration was between 4% and 6%. The basic effect at 15 J/cm2 was greater than that at 10 J/cm2. CONCLUSIONS: We concluded that antimicrobial chemotherapy activated by light with basic MB was effective in H. pylori eradication.

Candida albicans Sterilization Using a Light-Emitting Diode and Methylene Blue.

BACKGROUND AND AIMS: Conventional fungal treatment using external medication requires considerable time and effort. We herein examined the basic effect of methylene blue (MB) with sodium bicarbonate (NaHCO3) on Candida albicans sterilization using photodynamic antimicrobial chemotherapy (PACT). MATERIALS AND METHODS: NaHCO3 was added to MB to establish a basic pH. Then, C. albicans was smeared on a medium with basic MB followed by irradiation using a red light-emitting diode (LED) with a wavelength of 660 nm. The applied energy fluencies were 5, 10, 15, and 20 J/cm2. After 48 h of culture, the effects of the intervention were determined according to the fungal growth area. RESULTS: The basic effect appeared at a pH range of 8.6 to 8.9 and at 10 and 15 J/cm2, while the NaHCO3 concentration was between 1% and 2%. CONCLUSIONS: Our results suggested that PACT using basic MB was effective for C. albicans sterilization.