Impact of early intervention on health status outcomes in peripheral artery disease patients with chronic total occlusion lesions using the PORTRAIT registry.

OBJECTIVE: To analyze the impact of noninvasive and early invasive treatments on health status in patients with lower extremity peripheral arterial disease (PAD) without and with chronic total occlusions (CTOs) after 12 months of follow-up. METHODS: Using the international (the United States, the Netherlands, and Australia) observational longitudinal Patient-Centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories registry, we included patients with recent PAD symptoms between June 2011 and December 2015. We assessed the PAD-specific health status at initial visit and the 3-, 6-, and 12-month follow-up using the Peripheral Arterial Questionnaire. On a propensity matched-weighted cohort, we compared patients' characteristics by CTO status and treatment groups as early invasive (revascularization in the 3 months) vs noninvasive (exercise, medical therapies, or smoking cessation). We then assessed the health status trajectory over 12 months, as a three-way interaction between CTO status, treatment groups, and months, using a multilevel generalized linear regression model for repeated measures adjusted for baseline health status with random effects at the site and patient levels. RESULTS: We included 581 participants, with a mean age of 66.62 ± 9.33 years, 34.3% female, and 90.8% White, of whom 353 (60.8%) were without and 228 (39.2%) had a CTO lesion. Respectively, 96 (27.2%) and 70 (30.7%) patients underwent early invasive treatment (d = 0.07). Although patients with CTO were more likely to have lower resting ABI, multilevel disease, and to experience severe claudication vs their counterparts (|d| ≥ 0.20), patient health status at baseline with CTO was not different from those without CTO, with mean summary scores of 45.14 ± 20.26 vs 45.90 ± 21.24 (d = 0.04), respectively. The trajectory did not differ by CTO status (interaction CTO status × month; P = .517) and was higher in early invasive vs noninvasive treatment (treatment × month; P < .001), regardless of CTO status (CTO status × treatment; P = .981 and CTO status × treatment × month; P = .264). The score increased over time with the largest improvement occurring at 3 months in both noninvasive (non-CTO, +7.82 [95% confidence interval (CI), 4.03-11.60] and CTO, +9.27 95% CI, 4.45-14.09) and early invasive (non-CTO, +26.17 [95% CI, 20.06-32.28] and CTO, +24.52 [95% CI, 17.40-31.64] groups. The mean score in CTO vs non-CTO groups did not differ at each timepoint, with a 12-month mean score of 70.26 (95% CI, 67.87-74.65) vs 71.17 (95% CI, 65.91-76.44) (P = .99) in the noninvasive treatment and 84.93 (95% CI, 78.90-90.97) vs 79.20 (95% CI, 72.77-86.14) (P = .31) in the early invasive treatment. CONCLUSIONS: Patients with symptomatic PAD undergoing early revascularization exhibited better health status over time vs those undergoing noninvasive treatment strategy, irrespective of the presence of CTOs. The degree of the improvement was greater in the 3 months after the initial visit, especially in patients undergoing early revascularization.

Real-World Experience and Outcomes With Percutaneous Coronary Intervention for Protected Versus Unprotected Left Main Coronary Artery Disease: Insights from the Veteran Affairs Clinical Assessment Reporting and Tracking Program.

The practice patterns and outcomes of protected left main (PLM) and unprotected left main (ULM) percutaneous coronary intervention (PCI) are not well defined in contemporary US clinical practice. Data were collected from all Veteran Affairs catheterization laboratories participating in the Clinical Assessment Reporting and Tracking Program between 2009 and 2019. The analysis included 4,351 patients who underwent left main PCI, of whom 1,306 pairs of PLM and ULM PCI were included in a propensity-matched cohort. Selected temporal trends were also assessed. The primary outcome was major adverse cardiovascular event (MACE) outcomes at 1 year, which was defined as a composite of all-cause mortality, rehospitalization for myocardial infarction (MI), rehospitalization for stroke, or urgent revascularization. Patients who underwent ULM PCI compared with patients who underwent PLM PCI were older (age 71.5 vs 69.2 years, p <0.001), more clinically complex, and more likely to present with acute coronary syndrome. In the propensity-matched cohort, radial access was used more often for ULM PCI (21% [273] vs 14% [185], p <0.001) and ULM PCI was more likely to involve the left main bifurcation (22% vs 14%, p = 0.003) and require mechanical circulatory support (10% [134] vs 1% [17], p <0.001). The 1-year MACEs occurred more frequently with ULM PCI than PLM PCI (22% [289] vs 16% [215], p ≤0.001) and all-cause mortality was also higher (16% [213] vs 10% [125], p ≤0.001). In the matched cohort, there was a low incidence of rehospitalization for MI (4% [48] ULM vs 4% [48] PLM, p = 1.000) or revascularization (7% [94] ULM vs 6% [84] PLM, p = 0.485). In this real-world experience, patients who underwent PLM PCI had better 1-year outcomes than those who underwent ULM PCI; however, in both groups, there was a high rate of mortality and MACEs at 1 year despite a relatively low rate of MI or revascularization.

Outcomes of Percutaneous Coronary Intervention for Protected versus Unprotected Left Main Coronary Artery Disease: Insights from the VA CART Program.

Background: Practice patterns and outcomes of protected left main (PLM) and unprotected left main (ULM) percutaneous coronary intervention (PCI), as well as the differences between these types of PCI, are not well defined in real-world clinical practice. Methods: Data collected from all Veteran Affairs (VA) catheterization laboratories participating in the Clinical Assessment Reporting and Tracking Program between 2009 and 2019. The analysis included 4,351 patients undergoing left main PCI, of which 1,306 pairs of PLM and ULM PCI were included in a propensity matched cohort. Patients and procedural characteristics were compared between PLM and ULM PCI. Temporal trends were also assessed. Peri-procedural and one-year major adverse cardiovascular events (MACE) were compared using cumulative incidence plots. The primary outcome was MACE outcomes at 1-year, which was defined as a composite of all-cause mortality, rehospitalization for myocardial infarction (MI), rehospitalization for stroke or urgent revascularization. Results: ULM PCI patients in comparison to PLM PCI were older (71.5 vs 69.2; P < 0.001), more clinically complex and more likely to present with ACS. In the propensity matched cohort, radial access was used more often for ULM PCI (21% [273] vs. 14% [185], P < 0.001), and ULM PCI was more likely to involve the LM bifurcation (22% vs 14%; P = 0.003) and require mechanical circulatory support (10% [134] vs 1% [17]; P <0.001). One-year MACE occurred more frequently with ULM PCI compared to PLM PCI (22% [289] vs. 16% [215]; P = < 0.001) and all-cause mortality was also higher (16% [213] vs. 10% [125]; P = < 0.001). In the matched cohort there was a low incidence of rehospitalization for MI (4% [48] ULM vs. 4% [48] PLM; P = 1.000) or revascularization (7% [94] ULM vs. 6% [84] PLM; P = 0.485). Conclusions: Veterans undergoing PLM PCI had better one-year outcomes than those undergoing ULM PCI, but in both groups there was a high rate of mortality and MACE at one-year despite a relatively low rate of MI or revascularization.

Sex Differences in pLVAD-Assisted High-Risk Percutaneous Coronary Intervention: Insights From the PROTECT III Study.

BACKGROUND: Prior studies have found that female patients have worse outcomes following high-risk percutaneous coronary intervention (HRPCI). OBJECTIVES: The authors sought to evaluate sex-based differences in patient and procedural characteristics, clinical outcomes, and safety of Impella-supported HRPCI in the PROTECT III study. METHODS: We evaluated sex-based differences in the PROTECT III study; a prospective, multicenter, observational study of patients undergoing Impella-supported HRPCI. The primary outcome was 90-day major adverse cardiac and cerebrovascular events (MACCE)-the composite of all-cause death, myocardial infarction, stroke/transient ischemic attack, and repeat revascularization. RESULTS: From March 2017 to March 2020, 1,237 patients (27% female) were enrolled. Female patients were older, more often Black, more often anemic, and had more prior strokes and worse renal function, but higher ejection fractions compared to male patients. Preprocedural SYNTAX score was similar between sexes (28.0 ± 12.3). Female patients were more likely to present with acute myocardial infarction (40.7% vs 33.2%; P = 0.02) and more often had femoral access used for PCI and nonfemoral access used for Impella device implantation. Female patients had higher rates of immediate PCI-related coronary complications (4.2% vs 2.1%; P = 0.004) and a greater drop in SYNTAX score post-procedure (-22.6 vs -21.0; P = 0.04). There were no sex differences in 90-day MACCE, vascular complications requiring surgery, major bleeding, or acute limb ischemia. After adjustment using propensity matching and multivariable regression, immediate PCI-related complications was the only safety or clinical outcome that was significantly different by sex. CONCLUSIONS: In this study, rates of 90-day MACCE compared favorably to prior cohorts of HRPCI patients and there was no significant sex differences. (The PROTECT III Study is a substudy of The Global cVAD Study [cVAD]; NCT04136392).

Pulmonary Artery Catheter Use and Outcomes in Patients With ST-Elevation Myocardial Infarction and Cardiogenic Shock Treated With Impella (a Nationwide Analysis from the United States).

The role of continuous hemodynamic assessment with pulmonary artery (PA) catheter placement in cardiogenic shock (CS) remains debated. We aimed to assess the association between PA catheter placement and clinical outcomes in patients with CS secondary to ST-elevation myocardial infarction (STEMI) treated with an intravascular microaxial flow pump. We identified patients hospitalized with STEMI complicated by CS on mechanical circulatory support with an intravascular microaxial flow pump (Impella, Abiomed, Danvers, Massachusetts) using the National Inpatient Sample database and compared the outcomes in those treated with and without PA catheters. The primary outcome was in-hospital mortality. The secondary outcomes included in-hospital complications, hospital length of stay, inpatient costs, and temporal trends. The total cohort included 14,635 hospitalizations for STEMI complicated by CS treated with Impella between 2016 and 2020, of whom 5,505 (37.6%) received PA catheters. Over the study period, the use of PA catheters increased significantly from 25.9% to 41.8% (ptrend <0.01). Similarly, the use of Impella increased from 9.9% to 18.9% (ptrend <0.01). After adjustment for baseline characteristics using a multivariate logistic regression analysis, PA catheter use was associated with lower in-hospital mortality (adjusted odds ratio 0.80, 95% confidence interval 0.67 to 0.96, p = 0.01) and similar cardiovascular, neurologic, renal, and hematologic complications; length of stay; and inpatient costs compared with no PA catheter use. In conclusion, PA catheter use in patients with STEMI complicated by CS treated with Impella is associated with reduced in-hospital mortality and similar complication rates. Given the mortality benefit, further research is necessary to optimize PA catheter use in patients with STEMI with CS.

Real-world VASCADE closure device versus manual compression use and outcomes in patients with severe common femoral artery disease.

BACKGROUND: The VASCADE closure device deploys an extravascular collagen plug. Its use in those with access site disease undergoing peripheral vascular intervention (PVI) is unknown. We aimed to evaluate the efficacy and safety of the VASCADE closure device compared to manual compression (MC) in patients with moderate femoral access site disease. METHODS: We performed a single-center, retrospective review of patients undergoing PVI with at least moderate access site disease. Our institutional database was linked to the Vascular Quality Initiative database, and 200 patients were selected from a 1:1 propensity-matched cohort. Data on procedural metrics and outcomes up to 30-days were abstracted. RESULTS: There were 103 procedures that used VASCADE and 97 used MC. Baseline variables were similar between groups. The mean age was 68.2 ± 11.2 years and 37.6% were women. Closing mean activated clotting time (ACT) was shorter in VASCADE (198 s VASCADE vs. 213 s MC; p = 0.018). There was a nonsignificant decrease in external compression device use with VASCADE (VASCADE 19.0% vs. MC 28.1%; p = 0.15). At 30-days, there was a nonsignificant reduction in hematoma with VASCADE (3.8% vs. 7.8% MC; p = 0.25) and no difference in retroperitoneal bleeding (0.5%). Pseudoaneurysm rate was similar (1.3% VASCADE vs. 1.7% MC; p = 0.79). The 30-day mortality rate was similar between the two groups and not related to the procedure (1.3% VASCADE vs. 0.9% MC; p = 0.79). CONCLUSION: In patients undergoing PVI with at least moderate access site disease, safety and efficacy after using VASCADE was comparable with MC.

Increased Ca2+ influx through CaV1.2 drives aortic valve calcification.

Calcific aortic valve disease (CAVD) is heritable, as revealed by recent GWAS. While polymorphisms linked to increased expression of CACNA1C - encoding the CaV1.2 L-type voltage-gated Ca2+ channel - and increased Ca2+ signaling are associated with CAVD, whether increased Ca2+ influx through the druggable CaV1.2 causes CAVD is unknown. We confirmed the association between increased CaV1.2 expression and CAVD in surgically removed aortic valves from patients. We extended our studies with a transgenic mouse model that mimics increased CaV1.2 expression within aortic valve interstitial cells (VICs). In young mice maintained on normal chow, we observed dystrophic valve lesions that mimic changes found in presymptomatic CAVD and showed activation of chondrogenic and osteogenic transcriptional regulators within these valve lesions. Chronic administration of verapamil, a CaV1.2 antagonist used clinically, slowed the progression of lesion development in vivo. Exploiting VIC cultures, we demonstrated that increased Ca2+ influx through CaV1.2 drives signaling programs that lead to myofibroblast activation of VICs and upregulation of genes associated with aortic valve calcification. Our data support a causal role for Ca2+ influx through CaV1.2 in CAVD and suggest that early treatment with Ca2+ channel blockers is an effective therapeutic strategy.

Long term outcomes of ultrathin versus standard thickness second-generation drug eluting stents: Meta-analysis of randomized trials.

OBJECTIVE: Identify the effect of ultrathin drug eluting stents on long term outcomes in coronary artery disease. BACKGROUND: Although second-generation drug eluting stents (DES) are superior to first-generation DES, persistence of adverse outcomes has led to continued refinement in design. Ultrathin second-generation DES have been shown to improve outcomes at 1-year follow-up. Beyond 1-year their effect remains unknown. METHODS: PubMed, Embase and Cochrane Database were searched for randomized controlled trials that compared ultrathin (defined as <70 um) to standard thickness second-generation DES. Studies were chosen according to the PROSPERO protocol (CRD42020185374). Data from randomized controlled trials were pooled using random-effects model (Mantel-Haenszel). The primary outcome was target lesion failure (TLF) at 2 years, a composite of cardiac death, target vessel myocardial infarction, and ischemia-driven target vessel revascularization. Secondary outcomes included TLF at 3 and 5 years, the components of TLF and definite or probable stent thrombosis. Differences in outcomes between groups were presented in Forest plots as risk ratios (RR) with corresponding 95% confidence intervals (CIs) for each trial. RESULTS: We identified 18 publications from 10 trials with14,649 patients. At 2-years there was a significant 12% reduction in TLF (RR, 0.88; 95% CI 0.78-0.99; p < 0.05) associated with the use of ultrathin DES. At 3-years, there was a significant 19% reduction in TLF with ultrathin DES (RR, 0.79; 95% CI 0.64-0.98; p < 0.05). CONCLUSION: In patients undergoing percutaneous coronary intervention, ultrathin DES improve long term clinical outcomes.

Novel Supreme Drug-Eluting Stents With Early Synchronized Antiproliferative Drug Delivery to Inhibit Smooth Muscle Cell Proliferation After Drug-Eluting Stents Implantation in Coronary Artery Disease: Results of the PIONEER III Randomized Clinical Trial.

BACKGROUND: Accelerated endothelial healing after targeted antiproliferative drug delivery may limit the long-term inflammatory response of drug-eluting stents (DESs). The novel Supreme DES is designed to synchronize early drug delivery within 4 to 6 weeks of implantation, leaving behind a prohealing permanent base layer. Whether the Supreme DES is safe and effective in the short term and can improve long-term clinical outcomes is not known. METHODS: In an international, 2:1 randomized, single-blind trial, we compared treatment with Supreme DES to durable polymer everolimus-eluting stents (DP-EES) in patients with acute and chronic coronary syndromes. The primary end point was target lesion failure-a composite of cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization. The trial was designed to demonstrate noninferiority (margin of 3.58%) of the Supreme DES at 12 months compared with DP-EES (URL: https://www.clinicaltrials.gov; Unique identifier: NCT03168776). RESULTS: From October 2017 to July 2019, a total of 1629 patients were randomly assigned (2:1) to the Supreme DES (N=1086) or DP-EES (N=543). At 12 months, target lesion failure occurred in 57 of 1057 patients (5.4%) in the Supreme DES group and in 27 of 532 patients (5.1%) in the DP-EES group (absolute risk difference, 0.32% [95% CI, -1.87 to 2.5]; Pnoninferiority=0.002]. There were no significant differences in rates of device success, clinically driven target lesion revascularization, or stent thrombosis at 12 months, and the safety composite of cardiovascular death and target vessel myocardial infarction was 3.5% versus 4.6% (hazard ratio, 0.76 [95% CI, 0.46-1.25]) with Supreme DES compared with DP-EES, although rates of combined clinically and non-clinically driven target lesion revascularization at 12 months were higher with Supreme DES. CONCLUSIONS: Among patients with acute and chronic coronary syndromes undergoing percutaneous coronary intervention, the Supreme DES proved to be noninferior to the standard DP-EES. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03168776.

Racial and Socioeconomic Disparities in Cardiotoxicity Among Women With HER2-Positive Breast Cancer.

Breast cancer and cardiovascular-specific mortality are higher among blacks compared with whites, but disparities in cancer therapy-related adverse cardiovascular outcomes have not been well studied. We assessed for the contribution of race and socioeconomic status on cardiotoxicity among women with HER2-positive breast cancer. This retrospective cohort analysis studied women diagnosed with stage I-III HER2-positive breast cancer from 2004-2013. All underwent left ventricular ejection fraction assessment at baseline and at least one follow-up after beginning trastuzumab. Multivariable logistic regression was used to assess the association between race and socioeconomic status (SES) on cardiotoxicity, defined by clinical heart failure (New York Heart Association class III or IV) or asymptomatic left ventricular ejection fraction decline (absolute decrease ≥ 10% to < 53%, or ≥ 16%). Blacks had the highest prevalence of hypertension, diabetes, and increased BMI. Neighborhood-level SES measures including household income and educational attainment were lower for blacks compared with whites and others. The unadjusted cardiotoxicity risk was significantly higher in black compared with white women (OR, 2.10; 95% CI, 1.42 to 3.10). In a multivariable analysis, this disparity persisted after controlling for relevant cardiovascular risk factors (adjusted OR, 1.88; 95% CI, 1.25 to 2.84). Additional models adjusting for SES factors of income, educational attainment, and insurance status did not significantly alter the association between race and cardiotoxicity. In conclusion, black women are at increased risk of cardiotoxicity during HER2-targeted breast cancer therapy. Future etiologic analyses, particularly studies exploring biologic or genetic mechanisms, are needed to further elucidate and reduce racial disparities in cardiotoxicity.

Comparing a novel machine learning method to the Friedewald formula and Martin-Hopkins equation for low-density lipoprotein estimation.

BACKGROUND: Low-density lipoprotein cholesterol (LDL-C) is a target for cardiovascular prevention. Contemporary equations for LDL-C estimation have limited accuracy in certain scenarios (high triglycerides [TG], very low LDL-C). OBJECTIVES: We derived a novel method for LDL-C estimation from the standard lipid profile using a machine learning (ML) approach utilizing random forests (the Weill Cornell model). We compared its correlation to direct LDL-C with the Friedewald and Martin-Hopkins equations for LDL-C estimation. METHODS: The study cohort comprised a convenience sample of standard lipid profile measurements (with the directly measured components of total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], and TG) as well as chemical-based direct LDL-C performed on the same day at the New York-Presbyterian Hospital/Weill Cornell Medicine (NYP-WCM). Subsequently, an ML algorithm was used to construct a model for LDL-C estimation. Results are reported on the held-out test set, with correlation coefficients and absolute residuals used to assess model performance. RESULTS: Between 2005 and 2019, there were 17,500 lipid profiles performed on 10,936 unique individuals (4,456 females; 40.8%) aged 1 to 103. Correlation coefficients between estimated and measured LDL-C values were 0.982 for the Weill Cornell model, compared to 0.950 for Friedewald and 0.962 for the Martin-Hopkins method. The Weill Cornell model was consistently better across subgroups stratified by LDL-C and TG values, including TG >500 and LDL-C <70. CONCLUSIONS: An ML model was found to have a better correlation with direct LDL-C than either the Friedewald formula or Martin-Hopkins equation, including in the setting of elevated TG and very low LDL-C.

Utilizing electronic health data and machine learning for the prediction of 30-day unplanned readmission or all-cause mortality in heart failure.

Background: Existing risk assessment tools for heart failure (HF) outcomes use structured databases with static, single-timepoint clinical data and have limited accuracy. Objective: The purpose of this study was to develop a comprehensive approach for accurate prediction of 30-day unplanned readmission and all-cause mortality (ACM) that integrates clinical and physiological data available in the electronic health record system. Methods: Three predictive models for 30-day unplanned readmissions or ACM were created using an extreme gradient boosting approach: (1) index admission model; (2) index discharge model; and (3) feature-aggregated model. Performance was assessed by the area under the curve (AUC) metric and compared with that of the HOSPITAL score, a widely used predictive model for hospital readmission. Results: A total of 3774 patients with a primary billing diagnosis of HF were included (614 experienced the primary outcome), with 796 variables used in the admission and discharge models, and 2032 in the feature-aggregated model. The index admission model had AUC = 0.723, the index discharge model had AUC = 0.754, and the feature-aggregated model had AUC = 0.756 for prediction of 30-day unplanned readmission or ACM. For comparison, the HOSPITAL score had AUC = 0.666 (admission model: P = .093; discharge model: P = .022; feature aggregated: P = .012). Conclusion: These models predict risk of HF hospitalizations and ACM in patients admitted with HF and emphasize the importance of incorporating large numbers of variables in machine learning models to identify predictors for future investigation.

Cardiac outcomes of trastuzumab therapy in patients with HER2-positive breast cancer and reduced left ventricular ejection fraction.

PURPOSE: Asymptomatic decline in left ventricular ejection fraction (LVEF) or heart failure (HF) occurs in up to 25% of patients treated with trastuzumab and can result in incomplete breast cancer therapy. The cardiac safety of continuing trastuzumab in patients with asymptomatic LVEF decline is unknown. We report the cardiac outcomes of patients treated with trastuzumab after a significant asymptomatic LVEF decline. METHODS: Patients with HER2-positive breast cancer and asymptomatic LVEF decline to < 50% during trastuzumab were identified from an institutional echocardiogram database. Patients who received trastuzumab with a LVEF < 50% were classified as the continued group, whereas patients who had trastuzumab held until LVEF improved to ≥ 50% or who had trastuzumab permanently discontinued were classified as the interrupted group. Cardiac events were defined as HF (New York Heart Association class III-IV) or cardiovascular death. RESULTS: Sixty patients were included; the median age was 54 years. In 23 patients who continued trastuzumab, 14 (61%) tolerated trastuzumab without a cardiac event, 6 (26%) developed worsening LVEF (range 25-42%) leading to trastuzumab discontinuation, and three (13%) developed a cardiac event (1 HF, 2 possible/probable cardiovascular deaths). In 37 patients with interrupted trastuzumab, 15 (41%) were re-challenged with trastuzumab after LVEF improved to > 50%, 21 (57%) were not re-challenged, and one (3%) developed HF. More patients in the continued trastuzumab group had metastatic disease (39% vs. 5%, p = 0.002). The final LVEF after median follow-up of 633 days was similar between patients with trastuzumab continuation versus interruption (54% vs. 56%, p = 0.29). CONCLUSION: Continuation of trastuzumab after an asymptomatic LVEF decline to < 50% in patients who are expected to benefit from additional anti-HER2 therapy is a promising approach that warrants further investigation.

Management of ischemic coronary disease in patients receiving chemotherapy: an uncharted clinical challenge.

Acute coronary syndrome (ACS) coinciding with active malignancy presents a unique clinical challenge given intersecting pathophysiology and treatment-related effects. There is little established clinical guidance on management strategies, rendering most treatment approaches anecdotal. We present a case highlighting the complexity of managing a patient being treated for malignancy who concurrently suffers from ACS. We then review the literature on co-management of ACS and malignancy, including reports of specific cancer therapies associated with ACS, unique features of clinical presentation and optimal use of dual antiplatelet therapy to minimize risks of bleeding and thrombosis. We also describe gaps in current literature, challenges in systematically studying the clinical intersection of these disease processes and propose alternative methodologies for further research.

Extent of Vascular Remodeling Is Dependent on the Balance Between Estrogen Receptor α and G-Protein-Coupled Estrogen Receptor.

Estrogens are important regulators of cardiovascular function. Some of estrogen's cardiovascular effects are mediated by a G-protein-coupled receptor mechanism, namely, G-protein-coupled estrogen receptor (GPER). Estradiol-mediated regulation of vascular cell programmed cell death reflects the balance of the opposing actions of GPER versus estrogen receptor α (ERα). However, the significance of these opposing actions on the regulation of vascular smooth muscle cell proliferation or migration in vitro is unclear, and the significance in vivo is unknown. To determine the effects of GPER activation in vitro, we studied rat aortic vascular smooth muscle cells maintained in primary culture. GPER was reintroduced using adenoviral gene transfer. Both estradiol and G1, a GPER agonist, inhibited both proliferation and cell migration effects that were blocked by the GPER antagonist, G15. To determine the importance of the GPER-ERα balance in regulating vascular remodeling in a rat model of carotid ligation, we studied the effects of upregulation of GPER expression versus downregulation of ERα. Reintroduction of GPER significantly attenuated the extent of medial hypertrophy and attenuated the extent of CD45 labeling. Downregulation of ERα expression comparably attenuated the extent of medial hypertrophy and inflammation after carotid ligation. These studies demonstrate that the balance between GPER and ERα regulates vascular remodeling. Receptor-specific modulation of estrogen's effects may be an important new approach in modifying vascular remodeling in both acute settings like vascular injury and perhaps in longer term regulation like in hypertension.

Aldosterone mediates metastatic spread of renal cancer via the G protein-coupled estrogen receptor (GPER).

Although aldosterone is a known regulator of renal and cardiovascular function, its role as a regulator of cancer growth and spread has not been widely considered. This study tested the hypothesis that aldosterone regulates cancer cell growth/spread via G protein-coupled estrogen receptor (GPER) activation. In vitro in murine renal cortical adenocarcinoma (RENCA) cells, a widely used murine in vitro model for the study of renal cell adenocarcinoma, aldosterone increased RENCA cell proliferation to a maximum of 125 ± 3% of control at a concentration of 10 nM, an effect blocked by the GPER antagonist G15 or by GPER knockdown using short interfering (sh) RNA techniques. Further, aldosterone increased RENCA cell migration to a maximum of 170 ± 20% of control at a concentration of 100 nM, an effect also blocked by G15 or by GPER down-regulation. In vivo, after orthotopic RENCA cell renal transplantation, pulmonary tumor spread was inhibited by pharmacologic blockade of aldosterone effects with spironolactone (percentage of lung occupied by metastasis: control = 68 ± 13, spironolactone = 26 ± 8, P < 0.05) or inhibition of aldosterone synthesis with a high dietary salt diet (percentage of lung: control = 44 ± 6, high salt = 12 ± 3, P < 0.05), without reducing primary tumor size. Additionally, adrenalectomy significantly reduced the extent of pulmonary tumor spread, whereas aldosterone infusion recovered pulmonary metastatic spread toward baseline levels. Finally, inhibition of GPER either with the GPER antagonist G15 or by GPER knockdown comparably inhibited RENCA cell pulmonary metastatic cancer spread. Taken together, these findings provide strong evidence for aldosterone serving a causal role in renal cell cancer regulation via its GPER receptor; thus, antagonism of GPER represents a potential new target for treatment to reduce metastatic spread.-Feldman, R. D., Ding, Q., Hussain, Y., Limbird, L. E., Pickering, J. G., Gros, R. Aldosterone mediates metastatic spread of renal cancer via the G protein-coupled estrogen receptor (GPER).

G-protein estrogen receptor as a regulator of low-density lipoprotein cholesterol metabolism: cellular and population genetic studies.

OBJECTIVE: Estrogen deficiency is linked with increased low-density lipoprotein (LDL) cholesterol. The hormone receptor mediating this effect is unknown. G-protein estrogen receptor (GPER) is a recently recognized G-protein-coupled receptor that is activated by estrogens. We recently identified a common hypofunctional missense variant of GPER, namely P16L. However, the role of GPER in LDL metabolism is unknown. Therefore, we examined the association of the P16L genotype with plasma LDL cholesterol level. Furthermore, we studied the role of GPER in regulating expression of the LDL receptor and proprotein convertase subtilisin kexin type 9. APPROACH AND RESULTS: Our discovery cohort was a genetically isolated population of Northern European descent, and our validation cohort consisted of normal, healthy women aged 18 to 56 years from London, Ontario. In addition, we examined the effect of GPER on the regulation of proprotein convertase subtilisin kexin type 9 and LDL receptor expression by the treatment with the GPER agonist, G1. In the discovery cohort, GPER P16L genotype was associated with a significant increase in LDL cholesterol (mean±SEM): 3.18±0.05, 3.25±0.08, and 4.25±0.33 mmol/L, respectively, in subjects with CC (homozygous for P16), CT (heterozygotes), and TT (homozygous for L16) genotypes (P<0.05). In the validation cohort (n=339), the GPER P16L genotype was associated with a similar increase in LDL cholesterol: 2.17±0.05, 2.34±0.06, and 2.42±0.16 mmol/L, respectively, in subjects with CC, CT, and TT genotypes (P<0.05). In the human hepatic carcinoma cell line, the GPER agonist, G1, mediated a concentration-dependent increase in LDL receptor expression, blocked by either pretreatment with the GPER antagonist G15 or by shRNA-mediated GPER downregulation. G1 also mediated a GPER- and concentration-dependent decrease in proprotein convertase subtilisin kexin type 9 expression. CONCLUSIONS: GPER activation upregulates LDL receptor expression, probably at least, in part, via proprotein convertase subtilisin kexin type 9 downregulation. Furthermore, humans carrying the hypofunctional P16L genetic variant of GPER have increased plasma LDL cholesterol. In aggregate, these data suggest an important role of GPER in the regulation of LDL receptor expression and consequently LDL metabolism.

A common hypofunctional genetic variant of GPER is associated with increased blood pressure in women.

AIMS: Activation of vascular GPER has been linked to vasodepressor effects in animals. However, the significance of GPER regulation on chronic blood pressure control in humans is unknown. METHODS: To examine this question we determined the functional significance of expression of a common missense single nucleotide variant of GPER, P16L in vascular smooth muscle cells, and its association with blood pressure in humans. Further, to validate the importance of carrying GPER P16L in the development of hypertension we assessed allele frequency in a cohort of hard-to-treat hypertensive patients referred to a tertiary care clinic. RESULTS: Expression of the GPER P16L variant (V) vs. wild type (WT) in rat aortic vascular smooth muscle cells, was associated with a significant decrease in G1 (1 µm, a GPER agonist)-mediated ERK phosphorylation (slope of the function of G1-stimulated ERK phosphorylation: GPER content WT: 16.2, 95% CI 9.9, 22.6; V: 5.0, 95% CI 1.0, 9.0; P < 0.005) and apoptosis (slope of the function of G1-stimulated apoptosis: GPER content: WT: 4.4, 95% CI: 3.4, 5.4; V: 2.5, 95% CI 1.6, 2.3 P < 0.005). Normotensive female subjects, but not male subjects, carrying this hypofunctional variant (allele frequency 22%) have increased blood pressure [mean arterial pressure: P16/P16: 80 ± 1 mmHg (n = 204) vs. P16L carriers: 82 ± 1 mmHg (n = 127), 95% CI for difference: 0.6, 4.0 mmHg, P < 0.05], [systolic blood pressure: P16/P16: 105 ± 1 mmHg vs. P16L carriers: 108 ± 1 mmHg, 95% CI for difference:1.0, 5.1 mmHg, P < 0.05], [diastolic blood pressure: P16/P16: 66 ± 0.5 mmHg vs. P16L carriers 68 ± 0.7, 95% CI for difference: 0.2, 3.6 mmHg, P < 0.05]. Further, the P16L allele frequency was almost two-fold higher in female vs. male hypertensive patients (31% vs. 16%, allele ratio 0.5, 95% CI 0.32, 0.76, P < 0.05). CONCLUSIONS: The common genetic variant, GPER P16L, is hypofunctional and female carriers of this allele have increased blood pressure. There was an increased prevalence in a population of hard-to-treat hypertensive female patients. Cumulatively, these data suggest that in females, impaired GPER function might be associated with increased blood pressure and risk of hypertension.