Prevalence and Prognostic Importance of Massive Tricuspid Regurgitation in Patients Undergoing Tricuspid Annuloplasty With Concomitant Left-Sided Valve Surgery: A Study on Rheumatic Valvular Heart Disease.

BACKGROUND: The presence of tricuspid regurgitation (TR) is very common in patients with concomitant left-sided valve disease. Recent studies have advocated an additional grading of massive TR that is beyond severe. The present study sought to characterize the spectrum of TR in patients undergoing tricuspid annuloplasty (TA) and to evaluate the prognostic value of TR severity for post-operative outcome following TA. METHODS: A total of 176 patients who underwent TA with combined left-sided valve surgery, secondary to rheumatic valvular heart disease, were prospectively evaluated. The severity of TR was quantified by effective regurgitant orifice area (EROA) using the proximal isovelocity surface area method. Patients were categorized as having non-massive TR (EROA < 0.6 cm2) or massive TR (EROA ≥ 0.6 cm2). Adverse outcome was defined as all-cause mortality or heart failure requiring hospital admission following TA. RESULTS: A total of 55 (31%) patients were considered to have massive TR. Patients with massive TR had a greater right ventricular dimension but a smaller left ventricular dimension compared with those with non-massive TR. After a median follow-up of 39 months, 35 adverse events occurred. Cox-regression analysis showed that both continuous EROA and dichotomized EROA (massive vs. non-massive TR) were independently associated with adverse events even after multivariable adjustment. Further, Harrell C index demonstrated that the addition of massive TR provided better discrimination ability of a prediction model to known prognosticators following TA. CONCLUSIONS: Massive TR is common and up to 31% of study population had massive TR. Massive TR was associated with adverse outcome in patients undergoing TA. Classification of the severity of TR by quantitative measures and identification of massive TR in patients with concomitant left-sided valve disease are essential when considering the optimal timing of corrective surgery.

Prognostic value and reversibility of liver stiffness in patients undergoing tricuspid annuloplasty.

BACKGROUND: Liver stiffness (LS) assessed by transient elastography is associated with adverse events in patients with heart failure. However, the predictive value of LS for adverse outcome is uncertain in patients undergoing tricuspid annuloplasty (TA). This study sought to evaluate the prognostic value and reversibility of LS in patients undergoing TA during left-sided valve surgery. METHODS AND RESULTS: A total of 158 patients who underwent TA were prospectively evaluated. Patients were divided into three groups according to tertile of LS. Adverse outcome was defined as heart failure that required hospital admission or all-cause mortality following TA. The median LS was 13.9 (inter-quartile range 8.1-22.3) kPa and independently correlated positively with tricuspid regurgitation (TR) severity, inferior vena cava diameter and negatively with tricuspid annular plane systolic excursion. During a median follow-up of 31 months, 49 adverse events occurred. Multivariable Cox regression analysis revealed that LS was an independent predictor of adverse events. Significant improvement in LS at 1-year post-TA (13.1-7.8 kPa, P < 0.01) was noted only in patients who had no adverse events, not in those who experienced heart failure (17.1-14.2 kPa, P = 0.87) and seems to be linked to an absence of TR recurrence. CONCLUSIONS: This study demonstrated that LS is predictive of adverse outcome and is reversible in patients undergoing TA without TR recurrence at 1 year. These findings suggest that assessing LS, an integrative correlate of right heart condition, may aid the pre-operative risk assessment of candidate for heart surgery including TA.

Pan-Asian Consensus on Calcium Hydroxyapatite for Skin Biostimulation, Contouring, and Combination Treatments.

BACKGROUND: Several usage guidelines for calcium hydroxylapatite (CaHA), a dermal filler material, exist for non-Asian patients, making it necessary to determine whether their findings and consensuses are applicable to Asian patients who have distinct anatomies, cultural preferences, and aesthetic requests. OBJECTIVE: We sought to develop a Pan-Asian consensus on CaHA use in skin biostimulation, contouring, and combination treatments for face and body indications. METHODS: A survey on CaHA usage for contouring and biostimulation indications in Asian patients was conducted, followed by discussions to establish consensus statements and topics for examination. RESULTS: Several aspects of facial shaping and contouring or skin biostimulation with CaHA were agreed on, including that dilution is not a key consideration, that microfocused ultrasound with visualisation precedes CaHA in same day or session treatments, and that cannulas should be used. Among the many agreements on interventions in specific facial and body areas, there were also disagreements due to the diverse Asian patient presentations, requests, and access to tools or products; for example, CaHA should be placed in the interfascial layer for temple contouring, CaHA should not be injected directly into the infraorbital area for safety, and diluted CaHA should be injected subdermally for nonfacial or whole-face biostimulation and contouring. CONCLUSION: Our disagreements highlight the diversity of Asian facial morphotypes and desired aesthetic outcomes and underscore the need for customized aesthetic strategies to accommodate the heterogeneity of Asian anatomies, cultural preferences, and aesthetic ideals. Establishing consensus statements on critical aspects of Asian patient considerations, efficacy and safety, is crucial. This document provides strategic guidance on the use of classic, diluted CaHA for biostimulation or undiluted Radiesse®(+) (Merz Pharma GmbH & Co. KGaA, Frankfurt, Germany) for lifting and contouring to ensure consistent CaHA delivery for successful patient outcomes.

Incidence of dual antiplatelet therapy interruption within 1 year after primary percutaneous coronary intervention in patients with acute ST elevation myocardial infarction.

BACKGROUND: After primary percutaneous coronary intervention (PPCI) in patients with acute ST elevation myocardial infarction (STEMI), dual antiplatelet therapy (DAPT) is recommended to continue for 1 year. Occasionally, DAPT interruption may be required due to bleeding issues or unplanned surgical procedures. OBJECTIVE: To systematically evaluate the incidence of DAPT interruption within 1 year after PPCI. METHODS AND RESULTS: This was a single-centre, retrospective registry study. Consecutive patients with STEMI who underwent PPCI from 2013 to 2017 (N=538) were recruited into the analysis. The primary outcome was the incidence of interruption of DAPT within 1 year from the index PPCI. Secondary outcomes included incidence of bleeding in 1 year and prevalence of high bleeding risk (HBR) criteria at index presentation. Within 1 year, 17.1% (84/490) of post-PPCI survivors needed DAPT interruption and 7.1% (35/490) had major bleeding (Bleeding Academic Research Consortium type 3 or 5). At index presentation, HBR criteria were present in 36.1% (194/538) of patients. On univariate analysis, age, female gender, anaemia, anticoagulation, diabetes, hypertension and being a non-smoker were associated with DAPT interruption. On multivariate analysis, age was the only independent factor to predict DAPT interruption. CONCLUSION: DAPT interruption was not uncommon after PPCI in patients with STEMI particularly in the elderly. This has implication on stent selection during PPCI, and further studies are required to investigate which type of stent may best suit our real-life patients with STEMI.

Guideline-Based Critical Care Pathway Improves Long-Term Clinical Outcomes in Patients with Acute Coronary Syndrome.

Implementation of a critical care pathway (CCP) for acute coronary syndrome (ACS) has been shown to improve early compliance to guideline-directed therapies and reduce early mortality. Nevertheless its long-term impact on the compliance with medications or clinical outcomes remains unknown. Between 2004 and 2015, 2023 consecutive patients were admitted to our coronary care unit with ACS. We retrospectively compared the outcomes of 628 versus 1059 patients (mean age 66.1 ± 13.3 years, 74% male) managed before and after full implementation of a CCP. Compared with standard care, implementation of the CCP significantly increased coronary revascularization and long-term compliance with guideline-directed medical therapy (both P < 0.01). After a mean follow-up of 66.5 ± 44.0 months, 46.7% and 22.2% patients admitted before and after implementation of the CCP, respectively, died. Kaplan-Meier analyses showed that patients managed by CCP had better overall survival (P = 0.03) than those managed with standard care. After adjustment for clinical covariates and coronary anatomy, CCP remained independently predictive of better survival from all-cause mortality [hazard ratio (HR): 0.75, 95%confidence intervals (CI): 0.62-0.92, P < 0.01]. Stepwise multivariate cox regression model showed that both revascularization (HR: 0.55, 95%CI: 0.45-0.68, P < 0.01) and compliance to statin (HR: 0.70, 95%CI: 0.58-0.85, P < 0.01) were accountable for the improved outcome.

Prognostic Value of Tricuspid Valve Geometry and Leaflet Coaptation Status in Patients Undergoing Tricuspid Annuloplasty: A Three-Dimensional Echocardiography Study.

BACKGROUND: The advent of three-dimensional echocardiography (3DE) enables detailed evaluation of the tricuspid valve (TV) apparatus; nonetheless, the clinical value of preoperative 3DE is unknown in patients undergoing tricuspid annuloplasty (TA). The aim of this study was to evaluate the prognostic value of TV geometric parameters and leaflet coaptation status evaluated by 3DE in patients undergoing TA. METHODS: A total of 122 patients who underwent TA during left-sided heart valve surgery were prospectively evaluated. Detailed 3DE was performed before surgery. Adverse outcome was defined as the occurrence of heart failure requiring hospital admission or all-cause mortality following TA. RESULTS: A total of 33 adverse events (17 heart failures and 16 deaths) occurred during a median follow-up of 36 months. Tethering volume (hazard ratio = 1.32; 95% CI = 1.05-1.66; P = .01) and ratio of total leaflet length to closure length (hazard ratio = 1.07; 95% CI = 1.03-1.12; P < .01) were associated with adverse events after adjustment for age, sex, and tricuspid regurgitation vena contracta width. Receiver-operator characteristic curve analysis revealed that tethering volume (area under curve = 0.73) and ratio of total leaflet length to closure length (area under curve = 0.75) were most associated with adverse events at 1-year follow-up. The presence of either a large tethering volume or a low ratio of total leaflet length to closure length was predictive of an adverse outcome 1 year following TA. CONCLUSIONS: Our study suggests that 3DE-derived TV tethering volume and ratio of total leaflet length to closure length are important preoperative measures associated with adverse events in patients undergoing TA.

Metformin modifies disparity in hepatocellular carcinoma incidence in men with type 2 diabetes but without chronic liver diseases.

BACKGROUND: We assessed racial/ethnic disparity in hepatocellular carcinoma (HCC) incidence among men with type 2 diabetes (T2D) but without chronic liver diseases (CLD), and whether metformin use modified the disparity. METHODS: Study cohort: the nationwide Veterans Administration Health Care System electronic medical records among 40-89 years old men with T2D; without CLD, cancer, cardiovascular or renal diseases previously; insulin and thiazolidinedione naive. Logistic regression analyses compared HCC incidence between race/ethnicity groups under no metformin use adjusted for covariates and inverse propensity score weights (IPSW) for race/ethnicity. The generalizability technique integrated with IPSW was incorporated to compare covariates adjusted odds ratios (aOR) of HCC associated with metformin use among race/ethnicity groups. RESULTS: Study cohort: N = 84 433; 79.47% non-Hispanic white (NHW), 15.5% non-Hispanic African American (NHAA), 5.03% Hispanics; 36.76% metformin users; follow-up 6.10 ± 2.87 years; age 67.8 ± 9.8 years, HbA1c 6.57 ± 0.98%; 0.14% HCC cases. Under no metformin use, HCC incidence was lower for NHAA vs NHW (aOR = 0.60 [0.40-0.92]), similar between NHW and Hispanics. Metformin was associated with reduced HCC risk: aOR = 0.57 (0.40-0.81) for NHW; aOR = 0.35 (0.25-0.47) for NHAA; aOR = 0.31 (0.22-0.43) for Hispanics. Metformin dose >1000 mg/d was neutral for NHW; less effective for NHAA (P = 0.02); more effective for Hispanics (P = 0.002). CONCLUSIONS: In men with T2D but without CLD nor metformin use, HCC incidence was lower for NHAA compared to NHW or Hispanics; similar between NHW and Hispanics. Metformin use reduced HCC risk and modified the race/ethnicity disparity. IMPACT: Metformin's heterogeneous HCC prevention effect elucidates potential interventions to modify HCC disparity in patients with T2D.

Prognostic Value of Hepatorenal Function By Modified Model for End-stage Liver Disease (MELD) Score in Patients Undergoing Tricuspid Annuloplasty.

BACKGROUND: The Model for End-stage Liver Disease excluding international normalized ratio (MELD-XI) score and the modified MELD score with albumin replacing international normalized ratio (MELD-Albumin) score, which reflect both liver and renal function, have been reported as predictors of adverse events in liver and heart disease. Nonetheless, their prognostic value in patients undergoing tricuspid annuloplasty has not been addressed. METHODS AND RESULTS: A total of 394 patients who underwent tricuspid annuloplasty were evaluated. Baseline clinical, laboratory, and echocardiographic parameters were recorded. Adverse outcome was defined as the occurrence of heart failure requiring admission or all-cause mortality. Patients who underwent tricuspid annuloplasty had a high prevalence of preoperative hepatorenal dysfunction that was more common in patients with severe tricuspid regurgitation than those with mild to moderate tricuspid regurgitation. The MELD-XI and MELD-Albumin scores were excellent predictors of 1-year adverse outcome (area under the curve: 0.69 and 0.75, respectively). Kaplan-Meier survival curve demonstrated that a high score on MELD-XI (≥12.0) and MELD-Albumin (≥10.7) was associated with an increased risk of adverse events. During a median follow-up of 40 months, both MELD-XI and MELD-Albumin scores were significantly associated with adverse outcome, even after adjusting for potential confounding factors. Significant improvement of hepatorenal function at 1 year postoperation was noted only in patients who had no adverse events, not in those who experienced an adverse outcome. CONCLUSIONS: Both MELD-XI score and MELD-Albumin score can provide useful information to predict adverse outcome in patients undergoing tricuspid annuloplasty. The present study supports monitoring of modified MELD score to improve preoperative risk stratification of these patients.

Clinical Benefit of Valvular Surgery in Patients with Chronic Kidney Disease.

Concomitant chronic kidney disease (CKD) is common in patients with significant valvular heart disease (VHD). This study sought to evaluate the clinical benefit of valvular surgery in patients with concomitant CKD.We evaluated 349 patients with significant VHD who were referred for surgery. Patients were divided into those with CKD stage ≥ 3 (CKD patients; n = 88) and those with CKD stage 1 or 2 (no CKD patients; n = 261). 63 patients did not receive surgery, of which 20 patients had CKD and 43 had no CKD. Mortality and change in eGFR were assessed after a median follow-up of 21 months.In the whole study population, 25% of the patients had CKD and these patients had higher mortality than those with no CKD. The annual mortality rates of patients with CKD who did and did not undergo surgery were 7.9% and 28.0%, respectively. In patients with no CKD, the annual mortality rates of those who did and did not undergo surgery were 1.8% and 2.3%, respectively. Importantly, surgery was associated with significant survival benefit in patients with CKD (log-rank test, P < 0.01), but was neutral in patients with no CKD. Multivariable analysis confirmed the survival benefit of valvular surgery in all patients, which was most significant in patients with CKD. Furthermore, eGFR was preserved in patients who underwent valvular surgery but declined significantly in those who did not.CKD is common in patients with significant VHD and, if left untreated surgically, these patients exhibit a high mortality.

Establishment of healing profile and neointimal transformation in the new polymer-free biolimus A9-coated coronary stent by longitudinal sequential optical coherence tomography assessments: the EGO-BIOFREEDOM study.

AIMS: This study aimed to establish the early healing and neointimal transformation profile of the new polymer-free BioFreedom stent through sequential optical coherence tomography (OCT) within the first nine months following stent implantation. METHODS AND RESULTS: We randomly assigned 104 BFS recipients to one of five groups with angiography and OCT follow-up at 1, 2, 3, 4, or 5 months, together with another follow-up for all at nine months. The primary endpoint was the degree of OCT-detected strut coverage at nine months. From 1, 2, 3, 4, and 5 months, median neointimal strut coverage increased from 85.8, 87.0, 88.6, 96.8 to 97.1%, respectively, to 99.6% (IQR 98.2-99.9) at nine months. At nine months, median percent neointimal volume was 13.0% and angiographic late lumen loss was 0.21±0.30 mm. Major adverse cardiac events (MACE) were limited to one non-cardiac death, one non-ST-elevation myocardial infarction not related to BFS, and two target lesion revascularisations without stent thrombosis (MACE rate 4.0%). CONCLUSIONS: Neointimal strut coverage of the BFS was rapid and the BFS was shown to be clinically safe and effective.

The OCT-ORION Study: A Randomized Optical Coherence Tomography Study Comparing Resolute Integrity to Biomatrix Drug-Eluting Stent on the Degree of Early Stent Healing and Late Lumen Loss.

BACKGROUND: Durable polymers used in drug-eluting stents are considered a potential cause of hypersensitivity inflammatory response adversely affecting stent healing. Using a sequential follow-up with optical coherence tomography, we compared the differences in healing profiles of 2 drug-eluting stents with a biodegradable or durable polymer. METHODS AND RESULTS: Sixty patients with multivessel disease were prospectively enrolled to receive both study stents, which were randomly assigned to 2 individual vessels, a Resolute Integrity zotarolimus-eluting stent with a durable BioLinx polymer and a BioMatrix NeoFlex Biolimus A9-eluting stent with a biodegradable polylactic acid polymer. Optical coherence tomography was performed at baseline, then in 5 randomly assigned monthly groups at 2 to 6 months, and at 9 months in all patients. The primary end point was the difference in optical coherence tomography strut coverage at 9 months. Key secondary end points included angiographic late lumen loss and composite major adverse cardiac events (cardiac death, myocardial infarction, target lesion revascularization, and definite or probable stent thrombosis) at 9 months. Resolute Integrity zotarolimus-eluting stent showed significantly better strut coverage than BioMatrix NeoFlex Biolimus A9-eluting stent at 2 to 6 months (P<0.001) and less variance of percent coverage at 9 months, 99.7% (interquartile range, 99.1-100) versus 99.6% (interquartile range, 96.8-99.9; difference, 0.10; 95% confidence interval, 0.00-1.05; P<0.001). No significant difference was observed in major adverse cardiac events or angiographic end points. CONCLUSIONS: Despite having a durable polymer, Resolute Integrity zotarolimus-eluting stent exhibited better strut coverage than BioMatrix NeoFlex Biolimus A9-eluting stent having a biodegradable polymer; both showed similar antiproliferative efficacy. This novel, longitudinal, sequential optical coherence tomography protocol using each patient as own control could achieve conclusive results in small sample size. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01742507.

Predictive value of acute kidney injury for major adverse cardiovascular events following tricuspid annuloplasty: A comparison of three consensus criteria.

BACKGROUND: Tricuspid annuloplasty (TA) is increasingly being performed, but the clinical outcome is unsatisfactory. Acute kidney injury (AKI) is a common complication following cardiac surgery and predicts outcome. Nonetheless the occurrence rate and prognostic value of AKI after TA are unclear. METHODS: This study reviewed 339 consecutive patients (age 65±11 years; male 42%) who underwent TA. The incidence of AKI was defined according to risk/injury/failure/loss/end stage (RIFLE), acute kidney injury network (AKIN), and kidney disease improving global outcomes (KDIGO) criteria, respectively. Major adverse cardiovascular events (MACE) was defined as death, heart failure, stroke, and myocardial infarction (MI). The influence of AKI on MACE was evaluated as a short-term outcome and outcome beyond 30 days. RESULTS: The incidence of AKI, defined according to RIFLE, AKIN, and KDIGO was 57%, 52%, and 53%, respectively. MACE occurred in 94 cases (21 deaths, 63 heart failure requiring hospitalization, 7 stroke, and 3 MI). For short-term outcome, AKI defined by all three scoring systems was independently associated with MACE and death (p<0.01 for both), but not heart failure, stroke, or MI. For outcome beyond 30 days, AKI by all three criteria was associated with MACE and heart failure. Only AKI by AKIN and KDIGO, but not RIFLE, was independently associated with death. CONCLUSION: Our data suggest AKI affects over half of all patients who undergo TA, and has a major and long-lasting impact on survival, MACE, and heart failure. Use of AKIN and KDIGO is more useful than the RIFLE criteria when determining the prognostic value of AKI for mortality beyond 30 days.

One-year clinical outcomes of patients implanted with a Resolute Onyx™ zotarolimus-eluting stent.

Objective To evaluate the 1-year clinical outcomes of patients who received the Resolute Onyx™ stent. Methods This was a single-centre, retrospective registry analysis that reviewed the clinical data from all patients who were implanted with a Resolute Onyx™ stent between March 2015 and February 2016. Clinical follow-up was performed at 1 year post-implantation. Results A total of 252 patients received a Resolute Onyx™ stent and two patients were lost to follow-up. The mean age of the cohort was 66.9 years and 113 (45.2%) had diabetes mellitus. Thirty-eight patients (15.2%) had left main disease and 73 (29.2%) had three-vessel disease. A total of 175 patients (70.0%) had small vessel disease (<2.75 mm) and 210 (84.0%) had long lesions (>20 mm). The 1-year target lesion failure was 4.4% (11 of 250), cardiovascular death occurred in eight patients (3.2%), ischaemia-driven target lesion revascularization was undertaken in five patients (2.0%) and stent thrombosis occurred in one patient (0.4%). Conclusion The Resolute Onyx™ stent showed a favourable 1-year clinical performance in a real-world population.

Burden and contributing factors associated with tricuspid regurgitation: a hospital-based study.

OBJECTIVES: Tricuspid regurgitation (TR) is common in patients referred for cardiac assessment. Nonetheless, current estimates of its prevalence and contributing factors are limited. The aim of the present study was to evaluate the prevalence and demographics of TR in patients referred for echocardiography assessment at two University-affiliated hospitals. METHODS: A total of 6711 consecutive Chinese patients were recruited as part of the Chinese Valvular Heart Disease Study (CVATS). RESULTS: The most common valvular lesion was TR (54.7%), followed by mitral regurgitation (44.7%) and aortic regurgitation (26.5%). Clinically significant (moderate or severe) TR was identified in 8.4% with the proportion increased from 3.9% amongst those aged <51 to 15.9% in those aged ≥81. Multivariable adjustment demonstrated that significant TR was associated with age, congenital heart disease, chronic obstructive pulmonary disease, left-sided valvular heart disease (VHD), impaired left ventricular ejection fraction <50%, atrial fibrillation and pulmonary hypertension. CONCLUSIONS: Among all types of VHD, TR was the most common and was identified in over half of the subjects and clinically significant in 8.4%. These unique data provide contemporary clinical and epidemiological characteristics of TR in a large cohort of patients referred for cardiac assessment and confirm the increased burden of TR in the aged population.

Prevalence, Predictors and Clinical Outcome of Residual Pulmonary Hypertension Following Tricuspid Annuloplasty.

BACKGROUND: Tricuspid annuloplasty is increasingly performed during left heart valve surgery, but the long-term clinical outcome postoperatively is not satisfactory. The aim of this study was to determine whether residual pulmonary hypertension (PHT) contributes to the adverse outcome. METHODS AND RESULTS: One-hundred thirty-seven patients (age 61±11 years; men, 30%) who underwent tricuspid annuloplasty during left-side valve surgery were enrolled. The mean pulmonary artery systolic pressure before surgery was 49±13 mm Hg and 32±15 mm Hg following surgery. Patients were divided into 3 groups according to postoperative pulmonary artery systolic pressure: no residual PHT (n=78, 57%), mild residual PHT (n=43, 31%), or significant residual PHT (n=16, 12%). A preoperative larger right ventricular (RV) geometry and tricuspid valve tethering area were associated with mild or significant residual PHT. A total of 24 adverse events (20 heart failures and 4 cardiovascular deaths) occurred during a median follow-up of 25 months. Kaplan-Meier survival curve demonstrated that patients with significant residual PHT had the highest percentage of adverse events followed by those with mild residual PHT. Patients with no residual PHT had a very low risk of adverse events. Multivariable Cox regression analysis revealed that both mild (hazard ratio=4.94; 95% CI =1.34-18.16; P=0.02) and significant residual PHT (hazard ratio=8.67; 95% CI =2.43-30.98; P<0.01) were independent factors associated with adverse events. CONCLUSIONS: The present study demonstrated that 43% of patients who underwent tricuspid annuloplasty had residual PHT. The presence of mild or significant residual PHT was associated with adverse events in these patients.

Metformin for Reducing Racial/Ethnic Difference in Prostate Cancer Incidence for Men with Type II Diabetes.

Racial/ethnic disparity in prostate cancer is under studied in men with diabetes who are at a higher risk of aggressive prostate cancer. This study assessed the race/ethnic disparity in prostate cancer incidence for men with type II diabetes (T2D) and whether the impact of metformin on prostate cancer incidence varied by race/ethnicity. We conducted a retrospective study in 76,733 male veterans with T2D during 2003 to 2012. Cox proportional hazards model adjusting for covariates and propensity scores of metformin use and race/ethnic group membership was utilized to compute the HR of prostate cancer incidence associated with race/ethnicity and compare HR associated with metformin use between race/ethnic groups. Mean follow-up was 6.4 ± 2.8 years; 7% were Hispanics; 17% were African Americans (AA); mean age was 67.8 ± 9.8 years; 5.2% developed prostate cancer; and 38.9% used metformin. Among these diabetic men without metformin use, prostate cancer incidence was higher in Hispanics and AA than in non-Hispanic White (NHW). Use of metformin alone or metformin + statins was associated with a greater prostate cancer incidence reduction in Hispanics compared with NHW, but not between AA and NHW. Use of metformin + finasteride was associated with a greater prostate cancer incidence reduction in Hispanics and AA compared with NHW. Our results suggested that metformin treatment could be a potential strategy to reduce prostate cancer incidence in the minority populations who are at high risk for fatal prostate cancer. It will be important to further examine the pleiotropic effects of metformin in multi-race/ethnic prospective studies to better inform clinical management and potentially reduce racial/ethnic disparity in prostate cancer incidence among diabetic men. Cancer Prev Res; 9(10); 779-87. ©2016 AACR.