Lerman, Amir

Background The study compared downstream coronary and conduit disease progression in the left anterior descending coronary artery treated with coronary artery bypass grafting using the left internal mammary artery ( LIMA ) versus percutaneous coronary intervention with bare metal stent ( BMS ) or drug eluting stent ( DES ). Methods and Results A total of 12 301 consecutive patients underwent isolated primary coronary revascularization, of which 2386 met our inclusion criteria (Percutaneous coronary intervention, n=1450; coronary artery bypass grafting, n=936). Propensity score analysis matched 628 patients, of which 468 were treated to the left anterior descending with coronary artery bypass grafting with LIMA (n=314), percutaneous coronary intervention with BMS (n=94), and DES (n=60). Coronary angiograms were analyzed by quantitative coronary angiography ( QCA ; n=433). Cumulative downstream coronary and conduit disease progression were estimated by Kaplan–Meier method and effect of treatment type by Cox proportional hazard models. Patients treated with LIMA had significantly lower risk of downstream coronary disease progression at follow‐up angiogram compared with BMS and DES (hazard ratio [ HR ] [95% CI ], 0.34; [0.20–0.59]; P =0.0002; and HR [95% CI ], 0.39; [0.20–0.79]; P =0.01, respectively). LIMA was associated with a lower risk of conduit disease progression compared to BMS and DES ( HR [95% CI ], 0.18; [0.12–0.28]; P <0.001; and HR [95% CI ], 0.27; [0.16–0.46]; P <0.001, respectively). BMS was associated with higher HR for downstream coronary and conduit disease progression compared with DES , but the difference did not reach statistical significance ( HR [95% CI], 1.13; [0.57–2.36]; P =0.73; and HR [95% CI ], 1.46; [0.88–2.50]; P =0.14, respectively). Conclusions LIMA grafting to left anterior descending is associated with significantly lower risk of downstream coronary and conduit disease progression compared to percutaneous coronary intervention with BMS and DES .

Background The mechanisms of atrial fibrillation (AF) are highly divergent. The prevalence of AF increases significantly with age, and underling mechanisms might vary with age. Endothelial dysfunction may be associated with AF and atrial arrhythmia recurrence after catheter ablation. We tested the hypothesis that the impact of endothelial dysfunction on arrhythmia recurrence following catheter ablation is age dependent. Methods and Results This study enrolled 92 participants with AF undergoing catheter ablation. Endothelial function was assessed by peripheral arterial tonometry before ablation, and the natural logarithmic transformation of reactive hyperemia index was calculated. Endothelial dysfunction was defined as a natural logarithmic transformation of reactive hyperemia index <0.618 (median). Participants were followed for atrial tachycardia, flutter, and fibrillation recurrence for a median of 14 months. The mean age was 57±10 years. There was significant interaction between age and endothelial dysfunction in association with recurrence of AF ( P =0.029) and any atrial arrhythmia ( P =0.015), and the risk associated with endothelial dysfunction for arrhythmia recurrence was higher in younger versus older participants. Participants were divided into 2 age groups at a threshold of 60 years. Among participants aged ≤60 years, multivariate Cox proportional hazards analysis revealed the independent association between endothelial dysfunction and increased risk of arrhythmia recurrence (hazard ratio for AF 4.18 [95% CI 1.33–15.82], P =0.014, and for any atrial arrhythmia 3.62 [95% CI 1.29–11.81], P =0.014). Kaplan–Meier analysis showed that participants with endothelial dysfunction had significantly higher rates of recurrence of AF ( P =0.01) and any atrial arrhythmia ( P =0.002). Conclusions The risk associated with endothelial dysfunction for arrhythmia recurrence following catheter ablation was age dependent and was higher in younger participants.

Objectives Percutaneous coronary intervention (PCI) for acute coronary syndromes frequently fails to restore myocardial perfusion despite establishing epicardial vessel patency. Endothelin-1 (ET-1) is a potent vasoconstrictor, and its expression is increased in atherosclerosis and after PCI. In this study, we aim to define the role of endothelin in regulating coronary microvascular blood flow and myocardial perfusion following PCI in patients with non-ST elevation acute coronary syndromes (NSTACS), by assessing whether adjunctive therapy with a selective endothelin A (ETA) receptor antagonist acutely improves postprocedural coronary microvascular blood flow. Methods In a randomised, double-blinded, placebo-controlled trial, 23 NSTACS patients were enrolled to receive an intracoronary infusion of placebo (n=11) or BQ-123 (n=12) immediately before PCI. Post-PCI coronary microvascular blood flow and myocardial perfusion were assessed by measuring Doppler-derived average peak velocity (APV), and cardiac biomarker levels were quantified. Results Compared with the placebo group, APV was significantly higher in the drug group immediately after PCI (30 (20, 37) vs 19 (9, 26) cm/s; p=0.03). Hyperaemic APV, measured post-adenosine administration, was higher in the BQ-123 group, but the difference did not achieve statistical significance (56 (48, 72) vs 46 (34, 64) cm/s; p=0.090). Maximum coronary flow reserve postprocedure was not different between the two groups (2.1 (1.6, 2.3) vs 2.5 (1.8, 3.0)). Per cent change in creatine kinase isoenzyme MB from the time of PCI to 8 and 16 hours post-PCI was significantly lower in the drug group compared with the placebo group (−17 (−26, −10) vs 26 (−15, 134); p=0.02 and −17 (−38, 14) vs 107 (2, 446); p=0.007, respectively). Conclusions Endothelin is a mediator of microvascular dysfunction during PCI in NSTACS, and adjunctive selective ETA antagonist may augment myocardial perfusion during PCI. Trial registration number NCT00586820; Results.

Mitochondrial injury contributes to renal dysfunction in several models of renal disease, but its involvement in human hypertension remains unknown. Fragments of the mitochondrial genome released from dying cells are considered surrogate markers of mitochondrial injury. We hypothesized that hypertension would be associated with increased urine mitochondrial DNA (mtDNA) copy numbers. We prospectively measured systemic and urinary copy number of the mtDNA genes cytochrome-c oxidase-3 and NADH dehydrogenase subunit-1 by quantitative polymerase chain reaction in essential (n=25) and renovascular (RVH, n=34) hypertensive patients and compared them with healthy volunteers (n=22). Urinary kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin served as indices of renal injury. Renal blood flow and oxygenation were assessed by multidetector computed tomography and blood oxygen level–dependent magnetic resonance imaging. Blood pressure, urinary neutrophil gelatinase-associated lipocalin, and kidney injury molecule-1 were similarly elevated in essential hypertension and RVH, and estimated glomerular filtration rate was lower in RVH versus healthy volunteers and essential hypertension. Renal blood flow was lower in RVH compared with essential hypertension. Urinary mtDNA copy number was higher in hypertension compared with healthy volunteers, directly correlated with urinary neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 and inversely with estimated glomerular filtration rate. In RVH, urinary mtDNA copy number correlated directly with intrarenal hypoxia. Furthermore, in an additional validation cohort, urinary mtDNA copy number was higher in RVH compared with healthy volunteers (n=10 each). The change in serum creatinine levels and estimated glomerular filtration rate 3 months after medical therapy without or with revascularization correlated with the change in urinary mtDNA. Therefore, elevated urinary mtDNA copy numbers in hypertensive patients correlated with markers of renal injury and dysfunction, implicating mitochondrial injury in kidney damage in human hypertension.

Microvascular rarefaction distal to renal artery stenosis is linked to renal dysfunction and poor outcomes. Low–energy shockwave therapy stimulates angiogenesis, but the effect on the kidney microvasculature is unknown. We hypothesized that low–energy shockwave therapy would restore the microcirculation and alleviate renal dysfunction in renovascular disease. Normal pigs and pigs subjected to 3 weeks of renal artery stenosis were treated with six sessions of low–energy shockwave (biweekly for 3 consecutive weeks) or left untreated. We assessed BP, urinary protein, stenotic renal blood flow, GFR, microvascular structure, and oxygenation in vivo 4 weeks after completion of treatment, and then, we assessed expression of angiogenic factors and mechanotransducers (focal adhesion kinase and β 1-integrin) ex vivo . A 3-week low–energy shockwave regimen attenuated renovascular hypertension, normalized stenotic kidney microvascular density and oxygenation, stabilized function, and alleviated fibrosis in pigs subjected to renal artery stenosis. These effects associated with elevated renal expression of angiogenic factors and mechanotransducers, particularly in proximal tubular cells. In additional pigs with prolonged (6 weeks) renal artery stenosis, shockwave therapy also decreased BP and improved GFR, microvascular density, and oxygenation in the stenotic kidney. This shockwave regimen did not cause detectable kidney injury in normal pigs. In conclusion, low–energy shockwave therapy improves stenotic kidney function, likely in part by mechanotransduction-mediated expression of angiogenic factors in proximal tubular cells, and it may ameliorate renovascular hypertension. Low–energy shockwave therapy may serve as a novel noninvasive intervention in the management of renovascular disease.

Background Renovascular hypertension ( RVH ) impairs cardiac structure and left ventricular ( LV ) function, but whether mitochondrial injury is implicated in RVH ‐induced myocardial damage and dysfunction has not been defined. We hypothesized that cardiac remodeling in swine RVH is partly attributable to cardiac mitochondrial injury. Methods and Results After 12 weeks of hypercholesterolemic ( HC )‐ RVH or control (n=14 each), pigs were treated for another 4 weeks with vehicle or with the mitochondrial‐targeted peptide ( MTP ), Bendavia (0.1 mg/kg subcutaneously, 5 days/week), which stabilizes mitochondrial inner‐membrane cardiolipin (n=7 each). Cardiac function was subsequently assessed by multidetector‐computed tomography and oxygenation by blood‐oxygen‐level–dependent magnetic resonance imaging. Cardiolipin content, mitochondrial biogenesis, as well as sarcoplasmic‐reticulum calcium cycling, myocardial tissue injury, and coronary endothelial function were assessed ex vivo. Additionally, mitochondrial cardiolipin content, oxidative stress, and bioenergetics were assessed in rat cardiomyocytes incubated with tert‐butyl hydroperoxide ( tBHP ) untreated or treated with MTP . Chronic mitoprotection in vivo restored cardiolipin content and mitochondrial biogenesis. Thapsigargin‐sensitive sarcoplasmic reticulum Ca 2+ ‐ ATP ase activity that declined in HC ‐ RVH normalized in MTP ‐treated pigs. Mitoprotection also improved LV relaxation (E/A ratio) and ameliorated cardiac hypertrophy, without affecting blood pressure or systolic function. Myocardial remodeling and coronary endothelial function improved only in MTP ‐treated pigs. In tBHP ‐treated cardiomyocytes, mitochondrial targeting attenuated a fall in cardiolipin content and bioenergetics. Conclusions Chronic mitoprotection blunted myocardial hypertrophy, improved LV relaxation, and attenuated myocardial cellular and microvascular remodeling, despite sustained HC ‐ RVH , suggesting that mitochondrial injury partly contributes to hypertensive cardiomyopathy.

Abstract Obesity is a major risk factor for a number of chronic diseases, including diabetes, cardiovascular diseases, and cancer. Expansion of the adipose mass requires adipocyte precursor cells that originate from multipotent adipose-derived stromal cells (ASCs), which in turn also participate in repair activities. ASC function might decline in a disease milieu, but it remains unclear whether ASC function varies during the development of obesity. We tested the hypothesis that microenvironmental inflammatory changes during development of metabolic disorders in obesity affect ASC function. Domestic pigs were fed with an atherogenic (n = 7) or normal (n = 7) diet for 16 weeks. Abdominal adipose tissue biopsies were collected after 8, 12, and 16 weeks of diet for ASC isolation and immunohistochemistry of in situ ASCs and tumor necrosis factor-α (TNF-α). Longitudinal changes in proliferation, differentiation, and anti-inflammatory functions of ASCs were assessed. At 16 weeks, upregulated TNF-α expression in adipose tissue from obese pigs was accompanied by increased numbers of adipocyte progenitors (CD24+/CD34+) in adipose tissue and enlarged adipocyte size. In vitro, ASCs from obese pigs showed enhanced adipogenic and osteogenic propensity, which was abolished by anti-TNF-α treatment, whereas lean ASCs treated with TNF-α showed enhanced adipogenesis. Furthermore, obese ASCs showed increased senescence compared with lean ASCs, whereas their immunomodulatory capacity was preserved. Adipose tissue inflammation promotes an increase in resident adipocyte progenitors and upregulated TNF-α enhances ASC adipogenesis. Thus, adipose tissue anti-inflammatory strategies might be a novel target to attenuate obesity and its complications. Significance Adipose-derived stromal cell (ASC) function might decline in a disease milieu, but it remains unclear whether ASC function varies during the development of obesity. This study tested the hypothesis that microenvironmental inflammatory changes during development of metabolic disorders in obesity affect ASC function. It was found that ASCs show increased propensity for differentiation into adipocytes, which is partly mediated by upregulated tumor necrosis factor-α (TNF-α), likely in their adipose tissue microenvironment. Furthermore, TNF-α magnified obese ASC senescence, although it did not regulate their anti-inflammatory properties. Thus, adipose tissue inflammation might be a novel therapeutic target to avert ASC maldifferentiation and senescence.

Rationale: Coronary endothelial dysfunction (ED)—an early marker of atherosclerosis—increases the risk of cardiovascular events. Objective: We tested the hypothesis that cholesterol efflux capacity and high-density lipoprotein (HDL) particle concentration predict coronary ED better than HDL-cholesterol (HDL-C). Methods and Results: We studied 80 subjects with nonobstructive (<30% stenosis) coronary artery disease. ED was defined as <50% change in coronary blood flow in response to intracoronary infusions of acetylcholine during diagnostic coronary angiography. Cholesterol efflux capacity and HDL particle concentration (HDL-P IMA ) were assessed with validated assays. Cholesterol efflux capacity and HDL-P IMA were both strong, inverse predictors of ED ( P <0.001 and 0.005, respectively). In contrast, HDL-C and other traditional lipid risk factors did not differ significantly between control and ED subjects. Large HDL particles were markedly decreased in ED subjects (33%; P =0.005). After correction for HDL-C, both efflux capacity and HDL-P IMA remained significant predictors of ED status. HDL-P IMA explained cholesterol efflux capacity more effectively than HDL-C ( r =0.54 and 0.36, respectively). The efflux capacities of isolated HDL and serum HDL correlated strongly ( r =0.49). Conclusions: Cholesterol efflux capacity and HDL-P IMA are reduced in subjects with coronary ED, independently of HDL-C. Alterations in HDL-P IMA and HDL itself account for a much larger fraction of the variation in cholesterol efflux capacity than does HDL-C. A selective decrease in large HDL particles may contribute to impaired cholesterol efflux capacity in ED subjects. These observations support a role for HDL size, concentration, and function as markers—and perhaps mediators—of coronary atherosclerosis in humans.

Background Endothelial dysfunction is an early stage of atherosclerosis. Single‐nucleotide polymorphisms ( SNP s) have been associated with vascular dysfunction, cardiac events, and coronary artery remodeling. We aimed to detect SNP s associated with endothelial dysfunction and determine whether these associations are sex specific. Methods and Results Six hundred forty‐three subjects without significant obstructive coronary artery disease underwent invasive coronary endothelial function assessment. We collected data from 1536 SNP s that had previously been associated with vasoreactivity, angiogenesis, inflammation, artery calcification, atherosclerotic risk factors, insulin resistance, hormone levels, blood coagulability, or with coronary heart disease. Coronary vascular reactivity was assessed by the percent change in coronary artery diameter ≤ −20% after an intracoronary bolus injection of acetylcholine on invasive coronary physiology study. SNP s significantly associated with coronary epicardial endothelial dysfunction were ADORA 1 , KCNQ 1 , and DNAJC 4 in the whole cohort, LPA , MYBPH , ADORA 3 , and PON 1 in women and KIF 6 and NFKB 1 in men ( P <0.01). Conclusions We have identified several significant SNP s that are associated with an increased risk of coronary endothelial dysfunction. These associations appear to be sex specific and may explain gender‐related differences in development of atherosclerosis.

Introduction Apical ballooning syndrome (ABS) is typically associated with an antecedent stressful situation. Affected patients have been reported to have higher frequencies of premorbid affective disorders. We hypothesised that patients with ABS would have elevated levels of neuroticism (tendency to experience negative affect) and greater vulnerability to stress. Methods In this cross-sectional study, all active participants in the Mayo Clinic ABS prospective follow-up registry were invited to complete the third edition of the NEO Personality Inventory (NEO-PI-3). The NEO-PI-3 is the universally accepted measure of the ‘Five-Factor Model’ of personality. Inventory responses were scored using the NEO-PI-3 computer program and the data were compared with US normative sample used in standardisation of the inventory. Significance was set at 0.0014 to account for multiple comparisons. Results Of 106 registry participants approached, 53 completed the inventory. There was no difference in age, gender, time from ABS diagnosis, type of antecedent stressor (emotional, physical or none) or severity of initial illness between the responders and non-responders. Responders had mean Neuroticism T-scores of 48.0±10.6 (95% CI 45.1 to 50.9); p=0.18, when compared with the normal mean of 50. There was also no significant difference in the facet scale of Vulnerability: 46.9±8.4 (44.6 to 49.2), p=0.038, at α=0.0014. Conclusions Contrary to our hypothesis, patients with ABS do not manifest higher levels of neuroticism and do not have greater vulnerability to stress than the general population. These findings have implications for the clinicians’ perception of, and approach to, patients with ABS.