Microaxial Flow Pump or Standard Care in Infarct-Related Cardiogenic Shock.

BACKGROUND: The effects of temporary mechanical circulatory support with a microaxial flow pump on mortality among patients with ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock remains unclear. METHODS: In an international, multicenter, randomized trial, we assigned patients with STEMI and cardiogenic shock to receive a microaxial flow pump (Impella CP) plus standard care or standard care alone. The primary end point was death from any cause at 180 days. A composite safety end point was severe bleeding, limb ischemia, hemolysis, device failure, or worsening aortic regurgitation. RESULTS: A total of 360 patients underwent randomization, of whom 355 were included in the final analysis (179 in the microaxial-flow-pump group and 176 in the standard-care group). The median age of the patients was 67 years, and 79.2% were men. Death from any cause occurred in 82 of 179 patients (45.8%) in the microaxial-flow-pump group and in 103 of 176 patients (58.5%) in the standard-care group (hazard ratio, 0.74; 95% confidence interval [CI], 0.55 to 0.99; P = 0.04). A composite safety end-point event occurred in 43 patients (24.0%) in the microaxial-flow-pump group and in 11 (6.2%) in the standard-care group (relative risk, 4.74; 95% CI, 2.36 to 9.55). Renal-replacement therapy was administered to 75 patients (41.9%) in the microaxial-flow-pump group and to 47 patients (26.7%) in the standard-care group (relative risk, 1.98; 95% CI, 1.27 to 3.09). CONCLUSIONS: The routine use of a microaxial flow pump with standard care in the treatment of patients with STEMI-related cardiogenic shock led to a lower risk of death from any cause at 180 days than standard care alone. The incidence of a composite of adverse events was higher with the use of the microaxial flow pump. (Funded by the Danish Heart Foundation and Abiomed; DanGer Shock ClinicalTrials.gov number, NCT01633502.).

VARC-3 defined outcome of valve-in-valve transcatheter aortic valve implantation in stentless compared with stented aortic bioprostheses.

BACKGROUND: Valve-in-valve (ViV) transcatheter aortic valve implantation (TAVI) is a viable alternative to redo surgery in selected patients with bioprosthetic valve dysfunction. Most ViV-TAVI procedures have been performed in stented bioprosthetic valves (ST); stentless bioprostheses (SL) lack fluoroscopic markers and could be more challenging for ViV-TAVI. Data on more recent patients applying Valve Academic Research Consortium (VARC)-3 defined outcomes are scarce. We compared patient characteristics, procedural outcomes, and 5-year mortality of patients with SL versus ST aortic bioprosthetic valve failure undergoing ViV-TAVI. METHODS: Patients undergoing ViV-TAVI between 2007 and 2022 (52.5% of cases after 2015) at 3 German centers were included in this analysis. The co-primary outcome measures were technical success, device success, and early safety defined by VARC-3. Mortality was assessed up to 5 years. RESULTS: Overall, 43 (11.8%) SL and 313 (88.2%) ST ViV-TAVI were included. Patients were comparable with regard to age, sex, clinically relevant baseline comorbidities, and surgical risk. Technical success (SL: 83.7% versus ST: 79.9%, p = 0.552), device success (SL: 67.4% versus ST: 54.3%, p = 0.105), and early safety (SL: 74.4% versus ST: 66.5%, p = 0.296) were comparable between groups. The 30-day mortality (SL: 7.0% versus ST: 2.6%, p = 0.136) and 5-year mortality rates (SL: 23.3% versus ST: 24.6%, p = 0.874) were not significantly different between groups. CONCLUSION: SL and ST ViV-TAVI led to comparable short-term outcomes according to VARC-3- defined endpoints and similar mortality rates up to 5 years of follow-up. VARC-3 defined technical success, device success, and early safety as well as 5-year all-cause mortality in patients undergoing valve-in-valve transcatheter aortic valve implantation (ViV-TAVI) into stentless (SL) compared with stented (ST) failed aortic bioprostheses.

Impact of Enterococci vs. Staphylococci Induced Infective Endocarditis after Transcatheter Aortic Valve Implantation.

BACKGROUND: The two most common organisms found in infective endocarditis following transcatheter aortic valve implantation (TAVI-IE) are enterococci (EC-IE) and staphylococci (SC-IE). We aimed to compare clinical characteristics and outcomes of patients with EC-IE and SC-IE. METHODS: TAVI-IE patients from 2007 to 2021 were included in this analysis. The 1-year mortality was the primary outcome measure of this retrospective multi-center analysis. RESULTS: Out of 163 patients, 53 (32.5%) EC-IE and 69 (42.3%) SC-IE patients were included. Subjects were comparable with regard to age, sex, and clinically relevant baseline comorbidities. Symptoms at admission were not significantly different between groups, except for a lower risk for presenting with septic shock in EC-IE than SC-IE. Treatment was performed in 78% by antibiotics alone and in 22% of patients by surgery and antibiotics, with no significant differences between groups. The rate of any complication, in particular heart failure, renal failure, and septic shock during treatment for IE, was lower in EC-IE compared with SC-IE (p < 0.05). In-hospital (EC-IE: 36% vs. SC-IE: 56%, p = 0.035) and 1-year mortality (EC-IE: 51% vs. SC-IE: 70%, p = 0.009) were significantly lower in EC-IE compared with SC-IE. CONCLUSIONS: EC-IE, compared with SC-IE, was associated with a lower morbidity and mortality. However, absolute numbers are high, a finding that should trigger further research in appropriate perioperative antibiotic management and improvement of early IE diagnosis in the case of clinical suspicion.

Vessel fractional flow reserve (vFFR) for the assessment of stenosis severity: the FAST II study.

BACKGROUND: Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) is superior to angiography-guided PCI. The clinical uptake of FFR has been limited, however, by the need to advance a wire in the coronary artery, the additional time required and the need for hyperaemic agents which can cause patient discomfort. FFR derived from routine coronary angiography eliminates these issues. AIMS: The aim of this study was to assess the diagnostic performance and accuracy of three-dimensional quantitative coronary angiography (3D-QCA)-based vessel FFR (vFFR) compared to pressure wire-based FFR (≤0.80). METHODS: The FAST II (Fast Assessment of STenosis severity) study was a prospective observational multicentre study designed to evaluate the diagnostic accuracy of vFFR compared to the reference standard (pressure wire-based FFR ≤0.80). A total of 334 patients from six centres were enrolled. Both site-determined and blinded independent core lab vFFR measurements were compared to FFR. RESULTS: The core lab vFFR was 0.83±0.09 and pressure wire-based FFR 0.83±0.08. A good correlation was found between core lab vFFR and pressure wire-based FFR (R=0.74; p<0.001; mean bias 0.0029±0.0642). vFFR had an excellent diagnostic accuracy in identifying lesions with an invasive wire-based FFR ≤0.80 (area under the curve [AUC] 0.93; 95% confidence interval [CI]: 0.90-0.96; p<0.001). Positive predictive value, negative predictive value, diagnostic accuracy, sensitivity and specificity of vFFR were 90%, 90%, 90%, 81% and 95%, respectively. CONCLUSIONS: 3D-QCA-based vFFR has excellent diagnostic performance to detect FFR ≤0.80. The study was registered on clinicaltrials.gov under identifier NCT03791320.

Remote proctoring for high-risk coronary interventions with mechanical circulatory support during COVID-19 pandemic and beyond.

Remote proctoring by advanced digital technologies may help to overcome pandemic, geographic, and resource-related constraints for mentoring and educating interventional cardiology skills. We present a case series of patients undergoing high-risk percutaneous coronary intervention (HR-PCI) with mechanical circulatory support (MCS) guided by remote proctoring to gain insights into a streaming technology platform with regard to video/audio quality, visibility of all structural and imaging details, and delay in transmission. According to our experience, remote proctoring appears to be a reliable, quick, and resource-conserving way to disseminate, educate and improve MCS-supported HR-PCI with implications far beyond the COVID-19 pandemic.

Left-Atrial Appendage Thrombosis in Patients With Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation.

BACKGROUND: Data about the impact of left-atrial appendage thrombosis (LAAT) on early safety and mortality in patients undergoing transfemoral transcatheter aortic valve implantation (TF-TAVI) are scarce. We aimed to investigate the prevalence and predictors of LAAT and the outcome associated with this condition in patients treated by TF-TAVI. METHODS: Retrospective data analysis was derived from a prospective single-centre registry comparing patients with and without LAAT regarding early safety at 30 days, according to Valve Academic Research Consortium-2 (VARC-2) and 2-year mortality. RESULTS: LAAT was found in 7.6% of the whole cohort (n = 2527) and in 16.6% in those patients with known pre-existing atrial fibrillation (AF cohort, n = 1099). Compared with controls, patients with LAAT were sicker, indicated by a higher Society of Thoracic Surgeons (STS) score and burden of comorbidities. Neither VARC-2-defined early safety at 30 days nor the rate of stroke was different between LAAT and controls in both the whole (early safety: 29.2% vs 24.2%, P = 0.123; stroke: 5.9% vs 4.7%, P = 0.495) and AF cohort (early safety: 29.1% vs 22.9%, P = 0.072; stroke: 5.6% vs 3.3%, P = 0.142). Evaluating the whole cohort in a univariate analysis, the 2-year mortality was significantly higher in LAAT compared with controls (hazard ratio, 1.41; 95% confidence interval, 1.07-1.86; P = 0.014). However, multivariate analysis of the whole cohort and the AF cohort revealed no association between LAAT and 2-year mortality. CONCLUSIONS: LAAT was frequent in patients undergoing TF-TAVI- in particular, in patients with histories of AF-but it was not associated with an increase in periprocedural complications and did not predict 2-year mortality.

Treatment of failed aortic bioprostheses: An evaluation of conventional redo surgery and transfemoral transcatheter aortic valve-in-valve implantation.

BACKGROUND: The use of bioprostheses for surgical aortic valve replacement increased substantially within the last years. In case of prosthesis failure, re-SAVR is standard of care, whereas valve-in-valve deployment of a transfemoral transcatheter aortic valve prosthesis (VinV-TFAVI) has recently emerged as an alternative. We sought to evaluate early safety, clinical efficacy, and all-cause 1-year-mortality of VinV-TFAVI and redo surgery for failing aortic bioprostheses (re-SAVR). METHODS AND RESULTS: Patients receiving either VinV-TFAVI (n = 147) or re-SAVR (n = 111) for a degenerated aortic bioprosthesis between 01/2006 and 05/2017 were included in this analysis. All-cause 1-year mortality was the primary outcome measure. Early safety and clinical efficacy according to VARC-2 endpoint definitions were evaluated at 30 days. Baseline characteristics differed significantly between both groups including age, STS-PROM, and incidence of relevant comorbidities. Re-stenosis was the predominant mode of failure in 45.9% of re-SAVR and 63.1% of VinV-TFAVI patients. The rate of "early safety" endpoints was lower with VinV-TFAVI (17.7% vs. 64.9%, p < 0.01), the rate of "clinical efficacy" endpoints was lower, e.g. better with re-SAVR (53.1% vs. 32.4%, p < 0.01). All-cause 1-year-mortality (VinV-TFAVI 8.8% vs re-SAVR 9.9%, p = 0.84) was not different. Treatment strategy was not associated with 1-year-mortality in a Cox regression analysis. The incidence of prosthesis-patient-mismatch was higher in VinV-TFAVI compared to re-SAVR. CONCLUSION: VinV-TFAVI represents a viable alternative for treatment of degenerated aortic bioprostheses in patients at increased surgical risk. However, in patients at low risk for reoperation, a better clinical efficacy and acceptable safety may favour re-SAVR.

Baseline and Exercise Predictors of V˙O2peak in Systolic Heart Failure Patients: Results from SMARTEX-HF.

PURPOSE: This study aimed to investigate baseline, exercise testing, and exercise training-mediated predictors of change in peak oxygen uptake (V˙O2peak) from baseline to 12-wk follow-up (ΔV˙O2peak) in a post hoc analysis from the SMARTEX Heart Failure trial. METHODS: We studied 215 patients with heart failure with left ventricular ejection fraction (LVEF) ≤35%, and New York Heart Association (NYHA) classes II-III who were randomized to either supervised high-intensity interval training with exercise target intensity of 90%-95% of peak heart rate (HRpeak) or supervised moderate continuous training (MCT) with target intensity of 60%-70% of HRpeak, or who received a recommendation of regular exercise on their own. Predictors of ΔV˙O2peak were assessed in two models: a logistic regression model comparing highest and lowest tertiles (baseline parameters) and a multivariate linear regression model (test/training/clinical parameters). RESULTS: The change in V˙O2peak in response to the interventions (ΔV˙O2peak) varied substantially, from -8.50 to +11.30 mL·kg·min. Baseline NYHA (class II gave higher odds vs III; odds ratio (OR), 7.1 (2.0-24.9); P = 0.002), LVEF (OR per percent, 1.1 (1.0-1.2); P = 0.005), and age (OR per 10 yr, 0.5 (0.3-0.8); P = 0.003) were associated with ΔV˙O2peak.In the multivariate linear regression, 34% of the variability in ΔV˙O2peak was explained by the increase in exercise training workload, ΔHRpeak between baseline and 12-wk posttesting, age, and ever having smoked. CONCLUSION: Exercise training response (ΔV˙O2peak) correlated negatively with age, LVEF, and NYHA class. The ability to increase workload during the training period and increased ΔHRpeak between baseline and the 12-wk test were associated with a positive outcome.

Outcome of patients with previous coronary artery bypass grafting and severe calcific aortic stenosis receiving transfemoral transcatheter aortic valve replacement.

OBJECTIVES: To evaluate the impact of previous coronary artery bypass grafting (CABG) on early safety at 30 days and 1-year mortality in patients receiving transcatheter aortic valve replacement (TAVR). BACKGROUND: The use of TAVR in patients with previous CABG suffering from severe aortic stenosis has increased in the last years. METHODS: Consecutive TAVR patients were stratified according to previous CABG versus no previous cardiac surgery (control). All-cause 1-year mortality and early safety at 30 days were evaluated. RESULTS: In the unmatched cohort and compared to control (n = 2,364), CABG (n = 260) were younger, more often male and suffered more often from comorbidities leading to an increased STS-score (p < .001). The rate of early safety events at 30 days was comparable between CABG and control (21.2% vs. 24.6%, p = .22) with a higher mortality in CABG (9.6% vs. 5.3%, p = .005). All-cause 1-year mortality was higher in CABG compared to controls (HR 1.51 [95%-CI 1.15-1.97], p = .003). Applying Cox regression analysis, both 30-day (HR 1.57 [95%-CI 0.97-2.53], p = .067) and all-cause 1-year mortality (HR 1.24 [95%-CI 0.91-1.70], p = .174) were not significantly different between groups. After propensity-score matching, the rate of early safety events at 30 days was lower in CABG compared to controls (21.6% vs. 31.7%, p = .02). Thirty-day (9.1% vs. 7.7%, p = .596) and all-cause 1-year mortality (24.0% vs. 23.1%, p = .520, HR 1.14 [95%-CI 0.77-1.69], p = .520) were not different between groups. CONCLUSION: In patients receiving TAVR, previous CABG was not associated with an increase in periprocedural complications and all-cause 1-year mortality when adjusted for other comorbidities.

Continued Versus Interrupted Oral Anticoagulation During Transfemoral Transcatheter Aortic Valve Implantation and Impact of Postoperative Anticoagulant Management on Outcome in Patients With Atrial Fibrillation.

The role of continued versus interrupted oral anticoagulation (OAC) in patients with atrial fibrillation (AF) who underwent transfemoral transcatheter aortic valve implantation (TF-TAVI) for severe aortic stenosis is uncertain. The aim of this retrospective investigation was to evaluate the impact (1) of continued versus interrupted OAC on early safety and (2) of postoperative anticoagulant management on the 1-year mortality in patients with AF who underwent TF-TAVI. Consecutive patients with AF and on OAC at admission (n = 598) were stratified according to interrupted (iVKA) versus continued vitamin K antagonist (cVKA) versus continued direct oral anticoagulants (DOAC) at the time of TF-TAVI. Valve Academic Research Consortium-2 early safety was the primary outcome measure. Patients with iVKA (n = 299), cVKA (n = 117), and DOAC (n = 182) had comparable baseline characteristics including age (p = 0.25), gender (p = 0.33), and STS-Score (p = 0.072). The proportion of patients having a CHA2DS2-VASc-Score ≥3 (p = 0.791) and HAS-BLED-Score ≥3 (p = 0.185) was not different between groups. The rate of early safety events (with lower values indicating superior safety) was lowest in DOAC (13.2%) and not increased in cVKA (19.7%) compared to iVKA (23.1%) (p = 0.029). Valve Academic Research Consortium-2 defined stroke (p = 0.527) and bleeding (p = 0.097) did not differ between groups. Renal failure occurred more often in iVKA compared to cVKA and DOAC (p = 0.02). All-cause 1-year mortality was 20.1% in iVKA, 13.7% in cVKA, and 8.8% in DOAC (p = 0.015). Multivariate analysis revealed DOAC to be associated with reduced all-cause 1-year mortality (HR 0.56 (95%-CI 0.32 to 0.99), p = 0.047) whereas cVKA was comparable to iVKA (HR 0.75 (95%-CI 0.43 to 1.31), p = 0.307). In conclusion, cVKA did not increase the rate for the composite end point of early safety at 30 days in this cohort of patients. Treatment with a DOAC was associated with a significantly reduced rate of early safety end points at 30 days and lower 1-year mortality.

Gender-dependent association of diabetes mellitus with mortality in patients undergoing transcatheter aortic valve replacement.

BACKGROUND: Diabetes mellitus (DM) is a risk factor for cardiovascular disease. However, its effect on procedural and follow-up performance after transcatheter aortic valve replacement (TAVR) remains controversial. METHODS AND RESULTS: We performed an observational study of all consecutive patients treated with a transfemoral TAVR in a single-center cohort (n = 1818). All patients were stratified by diabetes status and gender. All-cause 3-year mortality was the primary endpoint. Male patients with DM were identified to have substantially increased 3-year mortality [125/314 (39.8%)] compared to males without DM [142/478 (29.7%), p < 0.01]. Male patients with DM had significantly higher 3-year mortality in comparison to female patients with (p < 0.01) or without DM (p < 0.01). There was no difference in 3-year mortality for female patients with [135/465 (29.0%)] and without DM [151/554 (27.3%); p = 0.70]. This increase in mortality in male DM patients was triggered by both cardiovascular and non-cardiovascular mortality. Furthermore, DM served as an independent predictor of 3-year mortality after TAVR selectively only in men. The interaction between male gender and diabetes mellitus was identified as an independent predictor of 3-year mortality [HR 1.88 (1.25; 2.82); p < 0.01]. DM did not affect 30-day mortality for the overall cohort and for males. CONCLUSION: Males with DM are a high-risk subgroup of patients after TAVR and require close medical attention including aggressive therapy of modifiable risk factors. Intensified diabetes management may improve long-term survival after TAVR.

Cardiac Surgery Compared With Antibiotics Only in Patients Developing Infective Endocarditis After Transcatheter Aortic Valve Replacement.

Background Infective endocarditis ( IE ) after transcatheter aortic valve replacement is a devastating complication associated with a high mortality. Our objective was to determine the impact of cardiac surgery (CS) and antibiotics ( IE - CS ) compared with medical treatment with antibiotics only ( IE - AB x) on 1-year mortality in patients developing IE after transcatheter aortic valve replacement. Methods and Results Patients developing IE after transcatheter aortic valve replacement were included in this retrospective analysis. All-cause 1-year mortality was the primary end point. A total of 20 patients underwent IE - CS compared with 44 patients treated by IE - AB x. In this unmatched cohort, patients treated by IE - AB x were older ( P=0.006), had a higher Society of Thoracic Surgeons score ( P=0.029), and more often had severe chronic kidney disease ( P=0.037). One-year mortality was not different between groups ( IE -CS versus IE-ABx, 65% versus 68.2%; P=0.802). The rate of any complication during treatment was higher in the IE - CS group ( P=0.024). In a matched cohort, baseline characteristics were not significantly different. All-cause 1-year mortality was not different between groups ( IE -CS versus IE-ABx, 65% versus 75%; P=0.490). A Cox regression analysis revealed any indication for surgery (hazard ratio, 6.20; 95% confidence interval, 1.80-21.41; P=0.004), sepsis on admission (hazard ratio, 4.03; 95% confidence interval, 1.97-8.24; P<0.001), and mitral regurgitation ≥2 (hazard ratio, 2.91; 95% confidence interval, 1.33-6.37) as factors associated with 1-year mortality. Conclusions In patients developing IE after transcatheter aortic valve replacement, mortality was predicted by the severity of IE and concomitant mitral regurgitation. In this small, and therefore statistically limited, but high-risk patient cohort, CS provided no significant mortality benefit compared with medical therapy. Individual decision making by a "heart and endocarditis team" is necessary to offer those patients the most reasonable treatment option.

Impact of active cancer disease on the outcome of patients undergoing transcatheter aortic valve replacement.

BACKGROUND: Patients undergoing transcatheter aortic valve replacement (TAVR) are often characterized by risk factors not reflected in conventional risk scores. In this context, little is known about the outcome of patients suffering from an active cancer disease (ACD). The objective was to determine the prevalence, clinical characteristics, perioperative outcomes, and mortality of patients with ACD undergoing TAVR compared to those with a history of cancer (HCD) and controls without known tumor disease. METHODS: TAVR patients between 02/2006 and 09/2014 were stratified according to the presence of ACD, HCD, and control. All-cause-mortality at 1-year was the primary end point. All end point definitions were subject to the Valve Academic Research Consortium II definitions. RESULTS: Overall, 1821 patients were included: 99 patients (5.4%) suffered from ACD and 251 patients (13.8%) had HCD. ACD was related to a solid organ or hematological source in 72.7% and 27.3%, respectively. Patients with ACD were more often male (P = 0.004) and had a lower logisticEuroScore I (P = 0.033). Overall rates of VARC-II defined periprocedural myocardial infarction, stroke, bleeding, access-site complications, and acute kidney injury were not different between groups. Thirty-day mortality did not differ between patients with ACD, HCD, and controls (6.1% vs 4.4% vs 7.6%, P = 0.176). All-cause 1-year mortality was higher in patients with ACD compared HCD and controls (37.4% vs 16.4% vs 20.8%, P < 0.001). ACD was an independent predictor of all-cause 1-year mortality (HR 2.10, 95%-CI 1.41-3.13, P < 0.001). CONCLUSION: The presence of ACD in patients undergoing TAVR is associated with significantly higher 1-year mortality.

Chronic ß1-adrenergic blockade enhances myocardial ß3-adrenergic coupling with nitric oxide-cGMP signaling in a canine model of chronic volume overload: new insight into mechanisms of cardiac benefit with selective ß1-blocker therapy.

The ß1-adrenergic antagonist metoprolol improves cardiac function in animals and patients with chronic heart failure, isolated mitral regurgitation (MR), and ischemic heart disease, though the molecular mechanisms remain incompletely understood. Metoprolol has been reported to upregulate cardiac expression of ß3-adrenergic receptors (ß3AR) in animal models. Myocardial ß3AR signaling via neuronal nitric oxide synthase (nNOS) activation has recently emerged as a cardioprotective pathway. We tested whether chronic ß1-adrenergic blockade with metoprolol enhances myocardial ß3AR coupling with nitric oxide-stimulated cyclic guanosine monophosphate (ß3AR/NO-cGMP) signaling in the MR-induced, volume-overloaded heart. We compared the expression, distribution, and inducible activation of ß3AR/NO-cGMP signaling proteins within myocardial membrane microdomains in dogs (canines) with surgically induced MR, those also treated with metoprolol succinate (MR+ßB), and unoperated controls. ß3AR mRNA transcripts, normalized to housekeeping gene RPLP1, increased 4.4 × 10(3)- and 3.2 × 10(2)-fold in MR and MR+ßB hearts, respectively, compared to Control. Cardiac ß3AR expression was increased 1.4- and nearly twofold in MR and MR+ßB, respectively, compared to Control. ß3AR was detected within caveolae-enriched lipid rafts (Cav3(+)LR) and heavy density, non-lipid raft membrane (NLR) across all groups. However, in vitro selective ß3AR stimulation with BRL37344 (BRL) triggered cGMP production within only NLR of MR+ßB. BRL induced Ser (1412) phosphorylation of nNOS within NLR of MR+ßB, but not Control or MR, consistent with detection of NLR-specific ß3AR/NO-cGMP coupling. Treatment with metoprolol prevented MR-associated oxidation of NO biosensor soluble guanylyl cyclase (sGC) within NLR. Metoprolol therapy also prevented MR-induced relocalization of sGCß1 subunit away from caveolae, suggesting preserved NO-sGC-cGMP signaling, albeit without coupling to ß3AR, within MR+ßB caveolae. Chronic ß1-blockade is associated with myocardial ß3AR/NO-cGMP coupling in a microdomain-specific fashion. Our canine study suggests that microdomain-targeted enhancement of myocardial ß3AR/NO-cGMP signaling may explain, in part, ß1-adrenergic antagonist-mediated preservation of cardiac function in the volume-overloaded heart.

Adiponectin promotes the migration of circulating angiogenic cells through p38-mediated induction of the CXCR4 receptor.

AIMS: Adiponectin (adipo) and exercise training (ET) contribute to the maintenance of a normal vascular tone by influencing vascular NO bioavailability and concentration and function of circulating angiogenic cells (CAC). The molecular mechanisms are only partially understood. Aim of the present study was to elucidate the effects of adipo on CAC migration and the underlying signaling pathways. Furthermore, the impact of ET on adiponectin-mediated CAC migration was investigated. METHODS AND RESULTS: CACs were isolated from peripheral blood and exposed to different adipo concentrations. Adipo (5µg/ml) enhanced the ability of CACs to migrate following an SDF-1 gradient by 345%. This was associated with a significant increase in CXCR4 expression on the surface of CACs as compared to control (10.1 ± 1.5 vs. 33.2 ± 4.5% CXCR4 positive cells, p<0.05). Adiponectin-induced CAC migration and CXCR4-upregulation were mediated through adipo-receptor 1 (AdipoR1) and blocked by an inhibitor of PI3-kinase, p38MAP kinase and NFκb. Adipo-stimulated migration of CACs, CXCR4 expression and p38MAPK-activation is impaired in patients with coronary artery disease (CAD). ET over 4 weeks partially corrects adiponectin-stimulated CAC migration and CXCR4 expression in patients with CAD (n=10). No change was observed in the control group (n=10). CONCLUSION: Adipo improves the migratory capacity of CACs in response to SDF1, partially through an upregulation of CXCR4. This is mediated through a pathway that involves binding of adipo to the AdipoR1 and subsequent PI3kinase/p38MAPK/ NFκb activation. In addition ET corrects the adiponectin responsiveness of CACs, and thereby might promote endogenous repair of damaged endothelium.

Exercise training restores the endothelial response to vascular growth factors in patients with stable coronary artery disease.

OBJECTIVE: Exercise training partially corrects endothelial dysfunction in patients with coronary artery disease (CAD). Growth factors like vascular endothelial growth factor (VEGF) as well as erythropoietin (EPO) are known to modulate the bioavailability of nitric oxide and, thereby, contribute to the maintenance of a normal vascular tone. The aim of the present study was to determine the impact of 4 weeks of exercise training on circulating growth factors and to elucidate their involvement in the training-induced changes in vasomotion in patients with CAD. METHODS AND RESULTS: A total of 39 patients were enrolled (training group: n = 20; control group: n = 19). At start of study and after 4 weeks, average peak flow velocity (APV) of the left internal mammary artery (LIMA) in response to acetylcholine was measured invasively in the treatment and control groups. Serum concentrations of VEGF and EPO were determined by enzyme-linked immunosorbent assay. After exercise training, LIMA APV in response to acetylcholine was increased by 93% (from 69 ± 17% at start of study to 133 ± 16% at 4 weeks, p < 0.01 vs. start of study and control). At start of study, there was no association between any of the vascular growth factors and endothelial function. However, after exercise training a close correlation was apparent between the acetylcholine-induced change in APV and EPO (r = 0.69, p < 0.01) and VEGF (r = 0.76, p < 0.01) serum concentrations. In the control group, these correlations were not evident and there was no change in endothelial function either. CONCLUSION: Exercise training improves agonist-mediated endothelium-dependent vasodilatation in CAD, partially through a restoration of the endothelial response to EPO and VEGF.