Marcus Sandri

Effects of Exercise and Ischemia on Mobilization and Functional Activation of Blood-Derived Progenitor Cells in Patients With Ischemic Syndromes Results of 3 Randomized Studies

Background—Exercise training (ET) has been shown to improve regional perfusion in ischemic syndromes. This might be partially related to a regeneration of diseased endothelium by circulating progenitor cells (CPCs) or CPC-derived vasculogenesis. The aim of the present study was to determine whether ischemic stimuli during ET are required to promote CPC mobilization in patients with cardiovascular diseases. Methods and Results—Patients with peripheral arterial occlusive disease (PAOD) were randomized to 4 weeks of daily ischemic ET or control (group A). Successfully revascularized patients with PAOD were randomized to 4 weeks of daily nonischemic ET or control (group B). Patients with stable coronary artery disease were subjected to 4 weeks of subischemic ET or control (group C). At baseline and after 4 weeks, the number of KDR+/CD34+ CPCs was determined by fluorescence-activated cell sorting analysis. Levels of vascular endothelial growth factor (VEGF) were measured by ELISA. A Matrigel assay was used to quantify CPC integration into vascular structures. Expression of the homing factor CXCR4 was determined by reverse transcription-polymerase chain reaction. In group A only, ischemic ET increased VEGF levels by 310% (P<0.05 versus control) associated with an increase in CPCs by 440% (P<0.05 versus control), increased CXCR4 expression, and enhanced integration of CPCs into endothelial networks. In contrast, subischemic ET in groups B and C increased CXCR4 expression and CPC integration. Conclusions—In training programs, symptomatic tissue ischemia seems to be a prerequisite for CPC mobilization. However, ischemic and subischemic ET programs affect CXCR4 expression of CPCs, which might lead to an improved CPC integration into endothelial networks.

The Leipzig Prospective Vascular Ultrasound Registry in Radial Artery Catheterization: Impact of Sheath Size on Vascular Complications

OBJECTIVES This study investigated the impact of sheath size on the rate of radial artery occlusions (RAO) (primary objective) and other access site complications (hemorrhage, pseudoaneurysm, arteriovenous fistula) as secondary objectives after transradial coronary catheterization. BACKGROUND The number of vascular access complications in the published data ranges from 5% to 38% after transradial catheterization. METHODS Between November 2009 and August 2010, 455 patients 65.3 ± 10.9 years of age (62.2% male) with transradial access with 5-F (n = 153) or 6-F (n = 302) arterial sheaths were prospectively recruited. Duplex sonography was obtained in each patient before discharge. Patients with symptomatic RAO were treated with low-molecular-weight heparin (LMWH), and a follow-up was performed. RESULTS The incidence of access site complications was 14.4% with 5-F sheaths compared with 33.1% with 6-F sheaths (p < 0.001). Radial artery occlusion occurred in 13.7% with 5-F sheaths compared with 30.5% with 6-F sheaths (p < 0.001). There was no difference between groups with regard to hemorrhage, pseudoaneurysms, or arteriovenous fistulas. Female sex, larger sheath size, peripheral arterial occlusive disease, and younger age independently predicted RAO in multivariate analysis. In total, 42.5% of patients with RAO were immediately symptomatic; another 7% became symptomatic within a mean of 4 days. Of patients with RAO, 59% were treated with LMWH. The recanalization rates were significantly higher in patients receiving LMWH compared with conventional therapy (55.6% vs. 13.5%, p < 0.001) after a mean of 14 days. CONCLUSIONS The incidence of RAO by vascular ultrasound was higher than expected from previous data, especially in patients who underwent the procedure with larger sheaths.

Exercise Training in Patients with Advanced Chronic Heart Failure (NYHA IIIb) Promotes Restoration of Peripheral Vasomotor Function, Induction of Endogenous Regeneration, and Improvement of Left-Ventricular Function

Background—Attenuated peripheral perfusion in patients with advanced chronic heart failure (CHF) is partially the result of endothelial dysfunction. This has been causally linked to an impaired endogenous regenerative capacity of circulating progenitor cells (CPC). The aim of this study was to elucidate whether exercise training (ET) affects exercise intolerance and left ventricular (LV) performance in patients with advanced CHF (New York Heart Association class IIIb) and whether this is associated with correction of peripheral vasomotion and induction of endogenous regeneration. Methods and Results—Thirty-seven patients with CHF (LV ejection fraction 24±2%) were randomly assigned to 12 weeks of ET or sedentary lifestyle (control). At the beginning of the study and after 12 weeks, maximal oxygen consumption (Vo2max) and LV ejection fraction were determined; the number of CD34+/KDR+ CPCs was quantified by flow cytometry and CPC functional capacity was determined by migration assay. Flow-mediated dilation was assessed by ultrasound. Capillary density was measured in skeletal muscle tissue samples. In advanced CHF, ET improved Vo2max by +2.7±2.2 versus −0.8±3.1 mL/min/kg in control (P=0.009) and LV ejection fraction by +9.4±6.1 versus −0.8±5.2% in control (P<0.001). Flow-mediated dilation improved by +7.43±2.28 versus +0.09±2.18% in control (P<0.001). ET increased the number of CPC by +83±60 versus −6±109 cells/mL in control (P=0.014) and their migratory capacity by +224±263 versus −12±159 CPC/1000 plated CPC in control (P=0.03). Skeletal muscle capillary density increased by +0.22±0.10 versus −0.02±0.16 capillaries per fiber in control (P<0.001). Conclusions—Twelve weeks of ET in patients with advanced CHF is associated with augmented regenerative capacity of CPCs, enhanced flow-mediated dilation suggestive of improvement in endothelial function, skeletal muscle neovascularization, and improved LV function. Clinical Trial Registration—http://www.clinicaltrials.gov. Unique Identifier: NCT00176384.

Exercise Training Attenuates MuRF-1 Expression in the Skeletal Muscle of Patients With Chronic Heart Failure Independent of Age The Randomized Leipzig Exercise Intervention in Chronic Heart Failure and Aging Catabolism Study

Background— Muscle wasting occurs in both chronic heart failure (CHF) and normal aging and contributes to exercise intolerance and increased morbidity/mortality. However, the molecular mechanisms of muscle atrophy in CHF and their interaction with aging are still largely unknown. We therefore measured the activation of the ubiquitin-proteasome system and the lysosomal pathway of intracellular proteolysis in muscle biopsies of CHF patients and healthy controls in two age strata and assessed the age-dependent effects of a 4-week endurance training program on the catabolic-anabolic balance. Methods and Results— Sixty CHF patients (30 patients aged ⩽55 years, mean age 46±5 years; 30 patients aged ≥65 years, mean age 72±5 years) and 60 healthy controls (30 subjects aged ⩽55 years, mean age 50±5 years; 30 subjects aged ≥65 years, mean age 72±4 years) were randomized to 4 weeks of supervised endurance training or to a control group. Before and after the intervention, vastus lateralis muscle biopsies were obtained. The expressions of cathepsin-L and the muscle-specific E3 ligases MuRF-1 and MAFbx were measured by real-time polymerase chain reaction and confirmed by Western blot. At baseline, MuRF-1 expression was significantly higher in CHF patients versus healthy controls (mRNA: 624±59 versus 401±25 relative units; P=0.007). After 4 weeks of exercise training, MuRF-1 mRNA expression was reduced by −32.8% (P=0.02) in CHF patients aged ⩽55 years and by −37.0% (P<0.05) in CHF patients aged ≥65 years. Conclusions— MuRF-1, a component of the ubiquitin-proteasome system involved in muscle proteolysis, is increased in the skeletal muscle of patients with heart failure. Exercise training results in reduced MuRF-1 levels, suggesting that it blocks ubiquitin-proteasome system activation and does so in both younger and older CHF patients. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00176319.

Cardioprotection by combined intrahospital remote ischaemic perconditioning and postconditioning in ST-elevation myocardial infarction: the randomized LIPSIA CONDITIONING trial.

AIMS Remote ischaemic conditioning (RIC) and postconditioning (PostC) are both potent activators of innate protection against ischaemia-reperfusion injury and have demonstrated cardioprotection in experimental and clinical ST-elevation myocardial infarction (STEMI) trials. However, their combined effects have not been studied in detail. The aim of this study was to evaluate if the co-application of intrahospital RIC and PostC has a more powerful effect on myocardial salvage compared with either PostC alone or control. METHODS AND RESULTS This prospective, controlled, single-centre study randomized 696 STEMI patients to one of the following three groups: (i) combined intrahospital RIC + PostC in addition to primary percutaneous coronary intervention (PCI); (ii) PostC in addition to PCI; and (iii) conventional PCI (control). The primary endpoint myocardial salvage index was assessed by cardiac magnetic resonance (CMR) imaging within 3 days after infarction. Secondary endpoints included infarct size and microvascular obstruction (MVO) assessed by CMR. The combined clinical endpoint consisted of death, reinfarction, and new congestive heart failure within 6 months. The primary endpoint myocardial salvage index was significantly greater in the combined RIC + PostC group when compared with the control group (49 [interquartile range 30-72] vs. 40 [interquartile range 16-68], P = 0.02). Postconditioning alone failed to improve myocardial salvage when compared with conventional PCI (P = 0.39). The secondary endpoints, including infarct size and MVO, showed no significant differences between groups. Clinical follow-up at 6 months revealed no differences in the combined clinical endpoint between groups (P = 0.44). CONCLUSION Combined intrahospital RIC + PostC in conjunction with PCI in STEMI significantly improves myocardial salvage in comparison with control and PostC. CLINICALTRIALSGOV NCT02158468.

Prognostic Value of Heart Rate Increase at Onset of Exercise Testing

Background— The initial response of heart rate to dynamic exercise has been proposed as having prognostic value in limited studies that have used modalities other than the treadmill. Our aim was to evaluate the prognostic value of early heart rate parameters in patients referred for routine clinical treadmill testing. Methods and Results— The heart rate rise at the onset of exercise was measured in 1959 patients referred for clinical treadmill testing at the Palo Alto (Calif) Veterans Affairs Medical Center from 1997 to 2004. Multivariable Cox survival analysis was performed for 197 all-cause and 74 cardiovascular deaths that accrued during a mean follow-up of 5.4±2.1 years. Decreased heart rate changes at all initial relative exercise workloads were associated with significantly increased all-cause mortality. The heart rate rise at one-third total exercise capacity, however, was the only early heart rate variable that significantly predicted both all-cause and cardiovascular risk after adjustment for confounders. Failing to reach 1 SD in the heart rate rise at one-third total exercise capacity was associated with a 28% increased all-cause mortality rate (hazard ratio, 0.72; 95% CI, 0.61 to 0.85; P<0.001) and a 35% cardiovascular mortality rate (hazard ratio, 0.65; 95% CI, 0.49 to 0.86; P=0.003). Of all heart rate measurements considered (initial and recovery), the heart rate increase at peak exercise was the most powerful predictor of cardiovascular prognosis after adjustment for potential confounders. The Duke treadmill score, however, was superior to all heart rate measurements in the prediction of cardiovascular mortality. Conclusions— In the present study population, a rapid initial heart rate rise was associated with improved survival, but the heart rate increase at peak exercise and other conventional measurements such as exercise capacity and the Duke treadmill score were more powerful predictors of prognosis.

PCI Strategies in Patients with Acute Myocardial Infarction and Cardiogenic Shock

Background In patients who have acute myocardial infarction with cardiogenic shock, early revascularization of the culprit artery by means of percutaneous coronary intervention (PCI) improves outcomes. However, the majority of patients with cardiogenic shock have multivessel disease, and whether PCI should be performed immediately for stenoses in nonculprit arteries is controversial. Methods In this multicenter trial, we randomly assigned 706 patients who had multivessel disease, acute myocardial infarction, and cardiogenic shock to one of two initial revascularization strategies: either PCI of the culprit lesion only, with the option of staged revascularization of nonculprit lesions, or immediate multivessel PCI. The primary end point was a composite of death or severe renal failure leading to renal‐replacement therapy within 30 days after randomization. Safety end points included bleeding and stroke. Results At 30 days, the composite primary end point of death or renal‐replacement therapy had occurred in 158 of the 344 patients (45.9%) in the culprit‐lesion‐only PCI group and in 189 of the 341 patients (55.4%) in the multivessel PCI group (relative risk, 0.83; 95% confidence interval [CI], 0.71 to 0.96; P=0.01). The relative risk of death in the culprit‐lesion‐only PCI group as compared with the multivessel PCI group was 0.84 (95% CI, 0.72 to 0.98; P=0.03), and the relative risk of renal‐replacement therapy was 0.71 (95% CI, 0.49 to 1.03; P=0.07). The time to hemodynamic stabilization, the risk of catecholamine therapy and the duration of such therapy, the levels of troponin T and creatine kinase, and the rates of bleeding and stroke did not differ significantly between the two groups. Conclusions Among patients who had multivessel coronary artery disease and acute myocardial infarction with cardiogenic shock, the 30‐day risk of a composite of death or severe renal failure leading to renal‐replacement therapy was lower among those who initially underwent PCI of the culprit lesion only than among those who underwent immediate multivessel PCI. (Funded by the European Union 7th Framework Program and others; CULPRIT‐SHOCK ClinicalTrials.gov number, NCT01927549.)

Exercise training leads to a reduction of elevated myostatin levels in patients with chronic heart failure

Background: In chronic heart failure (CHF), cardiac cachexia is often associated with the terminal stage of this disease. In animal studies it has been demonstrated that myostatin, a key regulator of skeletal muscle mass, is elevated in advanced stages of this syndrome. Design: The aim of the present study was to investigate the expression of myostatin in patients with late stage CHF (NYHA IIIb) in comparison to healthy subjects. Furthermore the effects of physical exercise on myostatin were analyzed. Methods: Twenty-four patients were either randomized to a sedentary control group (CHF-S) or exercise training (CHF-E). At baseline and after 12 weeks mRNA and myostatin protein in the peripheral skeletal muscle as well as myostatin serum concentration were measured. Furthermore 12 age-matched healthy men were compared to all patients at baseline (HC). Results: CHF patients showed a two-fold increase of myostatin mRNA (p = 0.05) and a 1.7-fold (p = 0.01) augmentation of protein content in skeletal muscle compared to healthy subjects. In late-stage CHF, exercise training led to a 36% reduction of the mRNA and a 23% decrease of the myostatin protein compared to baseline. The serum concentration of myostatin revealed no significant alteration between the groups. Conclusion: In the skeletal muscle, myostatin increases significantly in the course of CHF. The observed effects of a significant reduction of myostatin in skeletal muscle after 12 weeks of exercise training demonstrate the reversibility of molecular changes that might be able to halt the devastating process of muscle wasting in chronic heart failure.

Extracellular Volume Fraction for Characterization of Patients With Heart Failure and Preserved Ejection Fraction.

BACKGROUND Optimal patient characterization in heart failure with preserved ejection fraction (HFpEF) is essential to tailor successful treatment strategies. Cardiac magnetic resonance (CMR)-derived T1 mapping can noninvasively quantify diffuse myocardial fibrosis as extracellular volume fraction (ECV). OBJECTIVES This study aimed to elucidate the diagnostic performance of T1 mapping in HFpEF by examining the relationship between ECV and invasively measured parameters of diastolic function. It also investigated the potential of ECV to differentiate among pathomechanisms in HFpEF. METHODS We performed T1 mapping in 24 patients with HFpEF and 12 patients without heart failure symptoms. Pressure-volume loops were obtained with a conductance catheter during basal conditions and handgrip exercise. Transient pre-load reduction was used to extrapolate the diastolic stiffness constant. RESULTS Patients with HFpEF showed higher ECV (p < 0.01), elevated load-independent passive left ventricular (LV) stiffness constant (beta) (p < 0.001), and a longer time constant of active LV relaxation (p = 0.02). ECV correlated highly with beta (r = 0.75; p < 0.001). Within the HFpEF cohort, patients with ECV greater than the median showed a higher beta (p = 0.05), whereas ECV below the median identified patients with prolonged active LV relaxation (p = 0.01) and a marked hypertensive reaction to exercise due to pathologic arterial elastance (p = 0.04). On multiple linear regression analyses, ECV independently predicted intrinsic LV stiffness (β = 0.75; p < 0.01). CONCLUSIONS Diffuse myocardial fibrosis, assessed by CMR-derived T1 mapping, independently predicts invasively measured LV stiffness in HFpEF. Additionally, ECV helps to noninvasively distinguish the role of passive stiffness and hypertensive exercise response with impaired active relaxation. (Left Ventricular Stiffness vs. Fibrosis Quantification by T1 Mapping in Heart Failure With Preserved Ejection Fraction [STIFFMAP]; NCT02459626).

Exercise-Induced Modulation of Endothelial Nitric Oxide Production

In the arterial wall nitric oxide (NO) is the key transmitter for endothelium-dependent regulation of vascular tone. It is produced in intact endothelial cells by endothelial NO synthase (eNOS) as the key enzyme from L-arginine. Endothelial NO generation is highly regulated by mechanical, humoral, and metabolic factors. The regulation of NO synthesis occurs at different levels: ENOS gene polymorphisms are related to eNOS expression and activity and may potentially increase coronary event rate, mRNA expression is influenced by estrogen status and shear stress, mRNA stability is enhanced by vascular endothelial growth factor (VEGF), and final enzyme activity is regulated by the phosphorylation status at serine/threonine residues. Released from endothelial cells NO is rapidly transported to the neighboring vascular smooth muscle cells (VSMCs), where it induces the production of cGMP as a second messenger. CGMP in turn increases Ca2+ uptake into intracellular calcium stores thereby lowering [Ca2+]i and inducing VSMC relaxation and vasodilation. On its way to the VSMCs NO may be prematurely degraded by reactive oxygen species. On the other hand, chronic endurance exercise with regular bouts of increased laminar flow along the endothelium has the potential to increase eNOS mRNA expression and phosphorylation via AKT (protein kinase B) and to reduce oxidative stress by improving antioxidative protection. The growing knowledge about the complex regulation of NO synthesis and degradation in cardiovascular diseases and its response to exercise has led to a new understanding of the protective effects of long-term habitual physical activity against atherosclerotic heart disease and vascular aging.