Dapagliflozin Enhances Arterial and Venous Compliance During Exercise in Heart Failure With Preserved Ejection Fraction: Insights From the Cardiac and Metabolic Effects of Dapagliflozin in Heart Failure With Preserved Ejection Fraction Trial.

BACKGROUND: Systemic arterial compliance and venous capacitance are typically impaired in patients with heart failure with preserved ejection fraction (HFpEF), contributing to hemodynamic congestion with stress. Sodium-glucose cotransporter-2 inhibitors reduce hemodynamic congestion and improve clinical outcomes in patients with HFpEF, but the mechanisms remain unclear. This study tested the hypothesis that Dapagliflozin would improve systemic arterial compliance and venous capacitance during exercise in patients with HFpEF. METHODS: In this secondary analysis from the Cardiac and Metabolic Effects of Dapagliflozin in Heart Failure With Preserved Ejection Fraction Trial, 37 patients with HFpEF (mean age 68 ± 9 years, women 65%) underwent invasive hemodynamic exercise testing with simultaneous echocardiography at baseline and following treatment for 24 weeks with Dapagliflozin or placebo. Radial artery pressure (BP) was measured continuously using a fluid-filled catheter with transformation to aortic pressure, central hemodynamics were measured using high-fidelity micromanometers, and stressed blood volume was estimated from hemodynamic indices fit to a comprehensive cardiovascular model. RESULTS: There was no statistically significant effect of Dapagliflozin on resting BP, but Dapagliflozin reduced systolic BP during peak exercise (estimated treatment difference [ETD], -18.8 mm Hg [95% CI, -33.9 to -3.7] P=0.016). Reduction in BP was related to improved exertional total arterial compliance (ETD, 0.06 mL/mm Hg/m2 [95% CI, 0.003-0.11] P=0.039) and aortic root characteristic impedance (ETD, -2.6 mm Hg/mL*sec [95% CI: -5.1 to -0.03] P=0.048), with no significant effect on systemic vascular resistance. Dapagliflozin reduced estimated stressed blood volume at rest and during peak exercise (ETD, -292 mm Hg [95% CI, -530 to -53] P=0.018), and improved venous capacitance evidenced by a decline in ratio of estimated stressed blood volume to total blood volume (ETD, -7.3% [95% CI, -13.3 to -1.3] P=0.020). Each of these effects of Dapagliflozin at peak exercise were also observed during matched 20W exercise intensity. Improvements in total arterial compliance and estimated stressed blood volume were correlated with decreases in body weight, and reduction in systolic BP with treatment was correlated with the change in estimated stressed blood volume during exercise (r=0.40, P=0.019). Decreases in BP were correlated with reduction in pulmonary capillary wedge pressure during exercise (r=0.56, P<0.001). CONCLUSIONS: In patients with HFpEF, treatment with Dapagliflozin improved systemic arterial compliance and venous capacitance during exercise, while reducing aortic characteristic impedance, suggesting a reduction in arterial wall stiffness. These vascular effects may partially explain the clinical benefits with sodium-glucose cotransporter-2 inhibitors in HFpEF. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04730947.

Prevalence, Incidence, and Outcomes of Diastolic Dysfunction in Isolated Tricuspid Regurgitation: Perhaps Not Really "Isolated"?

BACKGROUND: In the absence of left-sided cardiac/pulmonary disease, functional tricuspid regurgitation (FTR) is referred to as isolated or idiopathic. Relationships between left ventricular diastolic dysfunction (DD) and FTR remain unknown. OBJECTIVES: The purpose of this study was to investigate the prevalence, incidence, and outcome of DD in patients with idiopathic FTR. METHODS: Adults without structural heart disease were identified. Severe DD was defined by ≥3 of 4 abnormal DD parameters (medial e', medial E/e', TR velocity, left atrial volume index) and ≥ moderate DD by ≥2. Propensity-score matching was performed (3:1) between each less-than-severe TR group and severe TR based on age, sex, body mass index, and comorbidities. RESULTS: Among 30,428 patients, FTR was absent in 73%, mild in 22%, moderate in 4%, and severe in 0.4%. In the propensity-matched sample, severe DD was present in 2%, 6%, 9%, and 13% patients, and ≥ moderate DD in 11%, 18%, 28%, and 48%, respectively (P < 0.001). The probability of heart failure with preserved ejection fraction using the H2FPEF score increased with increasing FTR (median 29.7%, 45.5%, 61.4%, and 88.7%, respectively), as did the prevalence of impaired left atrial strain <24% (35%, 48%, and 69% in mild, moderate, and severe TR). Incident severe and ≥ moderate DD developed more frequently with increasing FTR (HR: 8.45 [95% CI: 2.60-27.50] and HR: 2.82 [95% CI: 1.40-5.69], respectively for ≥ moderate vs no FTR) over a median of 3.0 years. Findings were confirmed in patients without lung disease or right ventricular enlargement. Over a median of 5.0 years, patients with ≥ moderate FTR and DD had the greatest risk of worse outcomes (multivariable P < 0.001). The association between TR and adverse outcomes was significantly diminished in the absence of DD. CONCLUSIONS: Diastolic dysfunction, increased heart failure with preserved ejection fraction probability, and impaired left atrial strain are commonly present in patients with idiopathic FTR, suggesting that the latter may not be truly isolated. Patients with FTR without DD or heart failure are at increased risk of incident DD. Patients with FTR and DD display worse outcomes.

Intratarsal Keratinous Cyst at the Eyelid Margin: A Case Report.

An uncommon case of an intratarsal keratinous cyst at the lid margin is described in a 73-year-old Asian man using long-term antiglaucoma eye drops. There was no history of trauma or surgery of the upper eyelid. A yellow solid mass attached to the tarsal plate had been located there for about 3 years. It imitated a sebaceous gland carcinoma or steatocystoma simplex. Excision biopsy showed cystic formation and leaked yellow creamy substance without hair. Histopathological and immunological findings helped make the diagnosis of an intratarsal keratinous cyst. To the best of our knowledge, this is the first case report of an intratarsal keratinous cyst at the lid margin.

Cardiac function, haemodynamics, and valve competence with exercise in patients with heart failure with preserved ejection fraction and mild to moderate secondary mitral regurgitation.

AIMS: This study aimed to evaluate the clinical significance of secondary mitral regurgitation (MR) in patients with heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS: We conducted a prospective study enrolling consecutively evaluated patients with HFpEF undergoing invasive haemodynamic exercise testing with simultaneous echocardiography. Compared to HFpEF without MR (n = 145, 79.7%), those with mild or moderate MR (n = 37, 20.3%) were older, more likely to be women, had more left ventricular (LV) systolic dysfunction, and more likely to have left atrial (LA) myopathy reflected by greater burden of atrial fibrillation, more LA dilatation, and poorer LA function. Pulmonary artery (PA) wedge pressure was higher at rest in HFpEF with MR (17 ± 5 mmHg vs. 20 ± 5 mmHg, p = 0.005), but there was no difference with exercise. At rest, only 2 (1.1%) patients had moderate MR, and none developed severe MR. Pulmonary vascular resistance was higher, and right ventricular (RV)-PA coupling was more impaired in patients with HFpEF and MR at rest and exercise. LV and LA myocardial dysfunction remained more severe in patients with MR during stress compared to those without MR, characterized by greater LA dilatation during all stages of exertion, lower LA emptying fraction and compliance, steeper and rightward-shifted LA pressure-volume relationships, and reduced LV longitudinal contractile function. CONCLUSIONS: Patients with HFpEF and mild or moderate MR have more severe LV systolic dysfunction, LA myopathy, RV-PA uncoupling, and more severe pulmonary vascular disease. Mitral valve incompetence in this setting is a phenotypic marker of more advanced disease but is not a causal factor in development of HFpEF.

Imaging and Mechanisms of Heart Failure with Preserved Ejection Fraction: A State of the Art Review.

Understanding of the pathophysiology of heart failure with preserved ejection fraction (HFpEF) has advanced rapidly over the past two decades. Currently, HFpEF is recognized as a heterogeneous syndrome, and there is a growing movement towards developing personalized treatments based on phenotype-guided strategies. Left ventricular dysfunction is a fundamental pathophysiological abnormality in HFpEF; however, recent evidence also highlights significant roles for the atria, right ventricle, pericardium, and extracardiac contributors. Imaging plays a central role in characterizing these complex and highly integrated domains of pathophysiology. This review focuses on established evidence, recent insights, and the challenges that need to be addressed concerning the pathophysiology of HFpEF, with a focus on imaging-based evaluations and opportunities for further research.

Autoimmune Disorders in Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Inflammation plays a fundamental role in the pathogenesis of heart failure with preserved ejection fraction (HFpEF). In most patients, inflammation develops secondary to cardiometabolic comorbidities, but in some, HFpEF develops in the setting of an underlying systemic inflammatory disease such as rheumatoid arthritis or systemic lupus erythematosus. OBJECTIVES: This study aimed to investigate the prevalence, pathophysiology, and outcome of patients with HFpEF and autoimmune or primary inflammatory disorders. METHODS: Of 982 consecutively evaluated patients with HFpEF diagnosed, 79 (8.0%) had autoimmune disorders. HFpEF was defined by invasive cardiopulmonary hemodynamic exercise testing. RESULTS: Female sex, higher heart rate, lower hemoglobin, absence of atrial fibrillation, and absence of coronary artery disease were independently associated with autoimmune disorders. Hemodynamics at rest and exercise did not differ between the groups, but peripheral oxygen extraction was lower in those with autoimmune disorders, reflected by lower arterial-venous oxygen content difference at rest (4.2 ± 0.7 mL/dL vs 4.6 ± 1.0 mL/dL; P < 0.001) and during exercise (9.3 ± 2.2 mL/dL vs 10.4 ± 2.2 mL/dL; P < 0.001), suggesting a greater peripheral deficit, and ventilatory efficiency (VE/VCo2 slope, regression slope relating minute ventilation to carbon dioxide output) was also more impaired (38.0 ± 7.9 vs 36.2 ± 7.3; P = 0.043). Patients with autoimmune disorders had a higher risk of death or heart failure (HF) hospitalization compared with those without in adjusted analyses (HR: 1.95 [95% CI: 1.17-3.27]; P = 0.011) over a median follow-up of 3.0 years, which was primarily attributable to higher risk of HF hospitalization (HR: 2.87 [95% CI: 1.09-7.57]; P = 0.033). CONCLUSIONS: Patients with HFpEF and autoimmune disorders have similar hemodynamic derangements but greater peripheral deficits in oxygen transport and higher risk for adverse outcome compared with those without.

Clinical phenogroup diversity and multiplicity: Impact on mechanisms of exercise intolerance in heart failure with preserved ejection fraction.

AIMS: We aimed to clarify the extent to which cardiac and peripheral impairments to oxygen delivery and utilization contribute to exercise intolerance and risk for adverse events, and how this relates to diversity and multiplicity in pathophysiologic traits. METHODS AND RESULTS: Individuals with heart failure with preserved ejection fraction (HFpEF) and non-cardiac dyspnoea (controls) underwent invasive cardiopulmonary exercise testing and clinical follow-up. Haemodynamics and oxygen transport responses were compared. HFpEF patients were then categorized a priori into previously-proposed, non-exclusive descriptive clinical trait phenogroups, including cardiometabolic, pulmonary vascular disease, left atrial myopathy, and vascular stiffening phenogroups based on clinical and haemodynamic profiles to contrast pathophysiology and clinical risk. Overall, patients with HFpEF (n = 643) had impaired cardiac output reserve with exercise (2.3 vs. 2.8 L/min, p = 0.025) and greater reliance on peripheral oxygen extraction augmentation (4.5 vs. 3.8 ml/dl, p < 0.001) compared to dyspnoeic controls (n = 219). Most (94%) patients with HFpEF met criteria for at least one clinical phenogroup, and 67% fulfilled criteria for multiple overlapping phenogroups. There was greater impairment in peripheral limitations in the cardiometabolic group and greater cardiac output limitations and higher pulmonary vascular resistance during exertion in the other phenogroups. Increasing trait multiplicity within a given patient was associated with worse exercise haemodynamics, poorer exercise capacity, lower cardiac output reserve, and greater risk for heart failure hospitalization or death (hazard ratio 1.74, 95% confidence interval 1.08-2.79 for 0-1 vs. ≥2 phenogroup traits present). CONCLUSIONS: Though cardiac output response to exercise is limited in patients with HFpEF compared to those with non-cardiac dyspnoea, the relative contributions of cardiac and peripheral limitations vary with differing numbers and types of clinical phenotypic traits present. Patients fulfilling criteria for greater multiplicity and diversity of HFpEF phenogroup traits have poorer exercise capacity, worsening haemodynamic perturbations, and greater risk for adverse outcome.

Exercise Capacity and Clinical Outcomes in Chronic Heart Failure Patients with Mild Tricuspid Regurgitation.

AIM: The present study aimed to investigate the impact of mild tricuspid regurgitation (TR) on the exercise capacity or clinical outcomes in patients with chronic heart failure (CHF). METHODS AND RESULTS: The study enrolled 511 patients with CHF who underwent cardiopulmonary exercise testing (CPET) between 2013 and 2018. The primary outcome was a composite of heart failure hospitalization and death. Patients with mild TR (n = 324) or significant TR (moderate or greater; n = 60) displayed worse NHYA class and reduced exercise capacity on CPET than those with non-TR (n = 127), but these were more severely impaired in patients with significant TR. A total of 90 patients experienced events over a median follow-up period of 3.3 (interquartile range 0.8-5.5) years. Patients with significant TR displayed a higher risk of events, while patients with mild TR had a 3.0-fold higher risk of events than patients with non-TR (hazard ratio (HR) 3.01; 95% confidence interval (CI), 1.50-6.07). Multivariate Cox regression analysis showed that, compared with non-TR, mild TR was associated with increased adverse events, even after adjustment for co-variates (HR 2.97; 95% CI, 1.35-6.55). CONCLUSIONS: TR severity was associated with worse symptoms, reduced exercise capacity, and poor clinical outcomes. Even patients with mild TR had worse clinical characteristics than those with non-TR.

Association of coronary plaque morphology with inflammatory biomarkers and target lesion revascularization in patients with chronic coronary syndrome: an optical coherence tomography study.

BACKGROUND: The characteristics of high-risk coronary atherosclerosis evaluated using optical coherence tomography (OCT) can have a prognostic role. Inflammatory biomarkers may be related to the severity of coronary artery disease. This study investigated the association of high-risk morphological features of coronary plaques on OCT with circulating levels of inflammatory biomarkers and target lesion revascularization (TLR). MATERIALS AND METHODS: We prospectively analyzed the data of 30 consecutive patients with chronic coronary syndrome who underwent percutaneous coronary intervention (PCI) using OCT. The levels of interleukin-6, tumor necrosis factor-alpha, high-sensitivity C-reactive protein, pentraxin 3, vascular endothelial growth factor, and monocyte chemoattractant protein-1 (MCP-1) were measured in plasma samples. Coronary plaque characteristics were scored quantitatively in the form of coronary plaque risk score (CPRS). The estimated high-risk plaque characteristics for TLR were plaque rupture, plaque erosion, calcified nodule, lipid-rich plaque, thin-cap fibroatheroma, cholesterol crystals, macrophage infiltration, microchannels, calcification angle >90°, and microcalcifications. Each high-risk feature carries 1 point. Patients were defined as having a low CPRS (CPRS ≤3) or a high CPRS (CPRS ≥4). RESULTS: The primary outcome was TLR. TLR occurred in 6 (20%) patients within 15 months of PCI. High CPRS on OCT was directly correlated with TLR (P=0.029). In logistic regression analysis, CPRS was associated with TLR (odds ratio, 10.0; 95% confidence interval, 1.34-74.5). Serum MCP-1 level was significantly correlated with the CPRS (P=0.020). CONCLUSIONS: In patients with chronic coronary syndrome, CPRS may be a surrogate predictor of TLR. Serum MCP-1 may aid in the detection of high-risk coronary atherosclerosis.

Differences in blood flow dynamics between balloon- and self-expandable valves in patients with aortic stenosis undergoing transcatheter aortic valve replacement.

BACKGROUND: The differences in pre- and early post-procedural blood flow dynamics between the two major types of bioprosthetic valves, the balloon-expandable valve (BEV) and self-expandable valve (SEV), in patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR), have not been investigated. We aimed to investigate the differences in blood flow dynamics between the BEV and SEV using four-dimensional flow cardiovascular magnetic resonance (4D flow CMR). METHODS: We prospectively examined 98 consecutive patients with severe AS who underwent TAVR between May 2018 and November 2021 (58 BEV and 40 SEV) after excluding those without CMR because of a contraindication, inadequate imaging from the analyses, or patients' refusal. CMR was performed in all participants before (median interval, 22 [interquartile range (IQR) 4-39] days) and after (median interval, 6 [IQR 3-6] days) TAVR. We compared the changes in blood flow patterns, wall shear stress (WSS), and energy loss (EL) in the ascending aorta (AAo) between the BEV and SEV using 4D flow CMR. RESULTS: The absolute reductions in helical flow and flow eccentricity were significantly higher in the SEV group compared in the BEV group after TAVR (BEV: - 0.22 ± 0.86 vs. SEV: - 0.85 ± 0.80, P < 0.001 and BEV: - 0.11 ± 0.79 vs. SEV: - 0.50 ± 0.88, P = 0.037, respectively); there were no significant differences in vortical flow between the groups. The absolute reduction of average WSS was significantly higher in the SEV group compared to the BEV group after TAVR (BEV: - 0.6 [- 2.1 to 0.5] Pa vs. SEV: - 1.8 [- 3.5 to - 0.8] Pa, P = 0.006). The systolic EL in the AAo significantly decreased after TAVR in both the groups, while the absolute reduction was comparable between the groups. CONCLUSIONS: Helical flow, flow eccentricity, and average WSS in the AAo were significantly decreased after SEV implantation compared to BEV implantation, providing functional insights for valve selection in patients with AS undergoing TAVR. Our findings offer valuable insights into blood flow dynamics, aiding in the selection of valves for patients with AS undergoing TAVR. Further larger-scale studies are warranted to confirm the prognostic significance of hemodynamic changes in these patients.

Association of longitudinal cardiac troponin trajectory with adverse events in patients with cardiac sarcoidosis.

BACKGROUND: Although high-sensitivity cardiac troponins may be sensitive and easily repeatable markers of disease activity in patients with cardiac sarcoidosis (CS), the association between longitudinal cardiac troponin trajectory and adverse events remains unclear. This study aimed to clarify whether longitudinal cardiac troponin levels were associated with adverse events in patients with CS. METHODS: We examined 63 consecutive CS-initiated prednisolone (PSL) patients with available longitudinal high-sensitivity cardiac troponin T (cTnT) data between December 2013 and March 2023. The area under the cTnT trajectory, which reflected cumulative cTnT release, was calculated to assess the association between longitudinal cTnT levels and adverse events. Patients were divided into two groups according to the median area under the cTnT trajectory per month. The primary outcome was a composite of sustained ventricular tachycardia or fibrillation, worsening heart failure, and sudden cardiac death (SCD). RESULTS: In total, 463 cTnT measurements were collected over a median follow-up period of 30.4 (interquartile range [IQR] 15.6-34.2) months. The primary outcome was observed in 12 (19%) patients. A higher area under the cTnT trajectory was significantly associated with an increased incidence of the primary outcome (P = 0.027), while cTnT levels before and one month after initiation of PSL, and these changes were not related to adverse events (P = 0.179, 0.096, and 0.95, respectively). CONCLUSIONS: Longitudinal cTnT trajectory following PSL initiation was associated with adverse cardiac events in patients with CS, suggesting that longitudinal measurement of cTnT would be useful for the early identification of high-risk patients.

Prognostic Value of Liver Fibrotic Markers in Patients With Heart Failure.

Several liver fibrotic markers are associated with prognosis in patients with heart failure (HF). However, the optimal markers for outcome prediction remain unclear. This study aimed to simultaneously investigate the prognostic value of liver fibrotic markers and the associations between these markers and clinical parameters in patients with HF without organic liver disease. We prospectively examined 211 consecutive patients with chronic HF between April 2018 and August 2021, excluding those with organic liver disease, using liver magnetic resonance imaging and ultrasound. A total of 7 representative liver fibrotic markers were measured in all patients. The primary outcome of interest was the composite of all-cause death and hospitalization for worsening HF. During a median follow-up period of 747 (interquartile range 465 to 1,042) days, the primary outcome occurred in 45 patients. Patients with higher hyaluronic acid and type III procollagen N-terminal peptide (P-III-P) levels showed a significantly higher incidence of the primary outcome than those without (p <0.001 and p = 0.005, respectively). The multivariable Cox regression analysis revealed that hyaluronic acid and P-III-P levels were independently associated with the risk of adverse events (hazard ratio 1.84, 95% confidence interval 1.18 to 2.87 and hazard ratio 2.89, 95% confidence interval 1.32 to 6.34, respectively) even after adjustment for a mortality prediction model, whereas the other 5 markers were not associated with the primary outcome. In conclusion, among the representative liver fibrotic markers, hyaluronic acid and P-III-P might be the optimal markers for outcome prediction in patients with HF.

Prognostic Significance of Peak Workload-to-Weight Ratio by Cardiopulmonary Exercise Testing in Chronic Heart Failure.

The prognostic impact of peak workload-to-weight ratio (PWR) during cardiopulmonary exercise testing (CPET) and its determinants in patients with chronic heart failure (CHF) are not well understood. Consecutive 514 patients with CHF referred for CPET at the Hokkaido University Hospital between 2013 and 2018 were identified. The primary outcome was a composite of hospitalization because of worsening heart failure and death. PWR was calculated as peak workload normalized to body weight (W/kg) by CPET. Patients with low PWR (cut-off median 1.38 [W/kg], n = 257) were older and more anemic than those with high PWR (n = 257). In CPET, patients with low PWR displayed reduced peak oxygen consumption and impaired ventilatory efficiency compared with those with high PWR, whereas the peak respiratory exchange ratio was not significantly different between the 2 groups. There were 89 patients with events over a median follow-up period of 3.3 (interquartile range 0.8 to 5.5) years. The incidence of composite events was significantly higher in patients with low PWR than in those with high PWR (log-rank p <0.0001). In the multivariable Cox regression, lower PWR was associated with adverse events (hazard ratio 0.31, 95% confidence interval 0.13 to 0.73, p = 0.008). Low hemoglobin concentration was strongly related to impaired PWR (ß coefficient = 0.43, per 1 g/100 ml increased, p <0.0001). In conclusion, PWR was associated with worse clinical outcomes, where blood hemoglobin was strongly related to PWR. Further study is required to identify therapies targeting peak workload achievements in exercise stress tests to improve the outcome in patients with CHF.

Impact of right ventricular reserve on exercise capacity and quality of life in patients with left ventricular assist device.

Although measuring right ventricular (RV) function during exercise is more informative than assessing it at rest, the relationship between RV reserve function, exercise capacity, and health-related quality of life (HRQoL) in patients with left ventricular assist devices (LVAD) remains unresolved. We aimed to investigate whether RV reserve assessed by the change in RV stroke work index (RVSWI) during exercise is correlated with exercise capacity and HRQoL in patients with LVAD. We prospectively assessed 24 consecutive patients with LVAD who underwent invasive right heart catheterization in the supine position. Exercise capacity and HRQoL were assessed using the 6-min walk distance (6 MWD) and peak oxygen consumption (V̇o2) in cardiopulmonary exercise testing, and the EuroQol visual analog scale (EQ-VAS), respectively. The patients were divided into two groups according to the median ΔRVSWI (change from rest to peak exercise). Patients with lower ΔRVSWI had significantly lower changes in cardiac index and absolute value of RV dP/dt than those with higher ΔRVSWI. The ΔRVSWI was positively correlated with 6 MWD (r = 0.59, P = 0.003) and peak V̇o2 (r = 0.56, P = 0.006). In addition, ΔRVSWI was positively correlated with the EQ-VAS (r = 0.44, P = 0.030). In contrast, there was no significant correlation between RVSWI at rest and 6 MWD (r = -0.34, P = 0.88), peak V̇o2 (r = 0.074, P = 0.74), or EQ-VAS (r = 0.127, P = 0.56). Our findings suggest that the assessment of RV reserve function is useful for risk stratification in patients with LVAD.NEW & NOTEWORTHY The change in right ventricular stroke work index (RVSWI) during exercise, not RVSWI at rest, was associated with exercise capacity and HRQoL. Our findings suggest that the assessment of change in RVSWI during exercise as a surrogate of RV reserve function may aid in risk stratification of patients with LVAD.

Analysis of the correlation between gene copy deletion in the AZFc region and male infertility in Japanese men.

Deletion of the azoospermia factor c (AZFc), located on the long arm of the Y chromosome, is a cause of male infertility. The structure of the Y chromosome is diversified by the copy number of various genes, such as deleted in azoospermia (DAZ), basic protein Y2, chromodomain Y1, testis-specific transcript Y-linked 4, and Golgi autoantigen golgin subfamily a2 like Y, located in the AZF region. In this study, we investigated the deletion of each gene copy and analyzed its relationship with Japanese male infertility. Deletions of single nucleotide variants of each gene copy in 721 proven fertile men as controls, 139 patients with non-obstructive azoospermia (NOA), and 56 patients with oligozoospermia (OS) were analyzed via polymerase chain reaction-restriction fragment length polymorphism analysis. Their association with infertility was analyzed using logistic regression analysis adjusted for the Y-chromosome haplogroup, D1a2a. Deletions of DAZ/II in the r1 region and DAZ/V in the r1 and r2 regions showed significant associations with NOA (odds ratio [OR] = 4.15, 95 % confidence interval [CI] = 1.18-14.6, P = 0.026; OR = 4.19, 95 % CI = 1.19-14.7, P = 0.025, respectively). They did not show any association with OS. Partial deletion of the AZFc region affects spermatogenesis in Japanese male.