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Dive into the research topics where Kreton Mavromatis is active.

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Featured researches published by Kreton Mavromatis.


The New England Journal of Medicine | 2012

Fractional flow reserve-guided PCI versus medical therapy in stable coronary disease

Bernard De Bruyne; Bindu Kalesan; Emanuele Barbato; Zsolt Piroth; Nikola Jagic; Sven Mobius-Winckler; Gilles Rioufol; Nils Witt; Petr Kala; Philip MacCarthy; Thomas Engstrøm; Keith G. Oldroyd; Kreton Mavromatis; Ganesh Manoharan; Peter Verlee; Ole Fröbert; Nick Curzen; Jane B. Johnson; Peter Jüni; William F. Fearon; Trial Investigators

BACKGROUND The preferred initial treatment for patients with stable coronary artery disease is the best available medical therapy. We hypothesized that in patients with functionally significant stenoses, as determined by measurement of fractional flow reserve (FFR), percutaneous coronary intervention (PCI) plus the best available medical therapy would be superior to the best available medical therapy alone. METHODS In patients with stable coronary artery disease for whom PCI was being considered, we assessed all stenoses by measuring FFR. Patients in whom at least one stenosis was functionally significant (FFR, ≤0.80) were randomly assigned to FFR-guided PCI plus the best available medical therapy (PCI group) or the best available medical therapy alone (medical-therapy group). Patients in whom all stenoses had an FFR of more than 0.80 were entered into a registry and received the best available medical therapy. The primary end point was a composite of death, myocardial infarction, or urgent revascularization. RESULTS Recruitment was halted prematurely after enrollment of 1220 patients (888 who underwent randomization and 332 enrolled in the registry) because of a significant between-group difference in the percentage of patients who had a primary end-point event: 4.3% in the PCI group and 12.7% in the medical-therapy group (hazard ratio with PCI, 0.32; 95% confidence interval [CI], 0.19 to 0.53; P<0.001). The difference was driven by a lower rate of urgent revascularization in the PCI group than in the medical-therapy group (1.6% vs. 11.1%; hazard ratio, 0.13; 95% CI, 0.06 to 0.30; P<0.001); in particular, in the PCI group, fewer urgent revascularizations were triggered by a myocardial infarction or evidence of ischemia on electrocardiography (hazard ratio, 0.13; 95% CI, 0.04 to 0.43; P<0.001). Among patients in the registry, 3.0% had a primary end-point event. CONCLUSIONS In patients with stable coronary artery disease and functionally significant stenoses, FFR-guided PCI plus the best available medical therapy, as compared with the best available medical therapy alone, decreased the need for urgent revascularization. In patients without ischemia, the outcome appeared to be favorable with the best available medical therapy alone. (Funded by St. Jude Medical; ClinicalTrials.gov number, NCT01132495.).


The New England Journal of Medicine | 2014

Fractional Flow Reserve–Guided PCI for Stable Coronary Artery Disease

Bernard De Bruyne; William F. Fearon; Nico H.J. Pijls; Emanuele Barbato; Pim A.L. Tonino; Zsolt Piroth; Nikola Jagic; Sven Mobius-Winckler; Gilles Rioufol; Nils Witt; Petr Kala; Philip MacCarthy; Thomas Engstrøm; Keith G. Oldroyd; Kreton Mavromatis; Ganesh Manoharan; Peter Verlee; Ole Fröbert; Nick Curzen; Jane B. Johnson; Andreas Limacher; Eveline Nüesch; Peter Jüni

BACKGROUND We hypothesized that in patients with stable coronary artery disease and stenosis, percutaneous coronary intervention (PCI) performed on the basis of the fractional flow reserve (FFR) would be superior to medical therapy. METHODS In 1220 patients with stable coronary artery disease, we assessed the FFR in all stenoses that were visible on angiography. Patients who had at least one stenosis with an FFR of 0.80 or less were randomly assigned to undergo FFR-guided PCI plus medical therapy or to receive medical therapy alone. Patients in whom all stenoses had an FFR of more than 0.80 received medical therapy alone and were included in a registry. The primary end point was a composite of death from any cause, nonfatal myocardial infarction, or urgent revascularization within 2 years. RESULTS The rate of the primary end point was significantly lower in the PCI group than in the medical-therapy group (8.1% vs. 19.5%; hazard ratio, 0.39; 95% confidence interval [CI], 0.26 to 0.57; P<0.001). This reduction was driven by a lower rate of urgent revascularization in the PCI group (4.0% vs. 16.3%; hazard ratio, 0.23; 95% CI, 0.14 to 0.38; P<0.001), with no significant between-group differences in the rates of death and myocardial infarction. Urgent revascularizations that were triggered by myocardial infarction or ischemic changes on electrocardiography were less frequent in the PCI group (3.4% vs. 7.0%, P=0.01). In a landmark analysis, the rate of death or myocardial infarction from 8 days to 2 years was lower in the PCI group than in the medical-therapy group (4.6% vs. 8.0%, P=0.04). Among registry patients, the rate of the primary end point was 9.0% at 2 years. CONCLUSIONS In patients with stable coronary artery disease, FFR-guided PCI, as compared with medical therapy alone, improved the outcome. Patients without ischemia had a favorable outcome with medical therapy alone. (Funded by St. Jude Medical; FAME 2 ClinicalTrials.gov number, NCT01132495.).


Circulation | 2000

Vascular Superoxide Production and Vasomotor Function in Hypertension Induced by Deoxycorticosterone Acetate–Salt

Mark J. Somers; Kreton Mavromatis; Zorina S. Galis; David G. Harrison

BACKGROUND Angiotensin II-induced hypertension is associated with increased vascular superoxide production, which contributes to hypertension caused by the octapeptide. In cell culture, stretch increases endothelial and vascular smooth muscle production of reactive oxygen species (ROS). In perfused isolated vessels, elevations of pressure can increase vessel angiotensin II production. The effects of low-renin hypertension on vascular ROS production remain unclear. Furthermore, the role of ROS in vascular function and hypertension in low-renin hypertension is undefined. METHODS AND RESULTS Rats were treated with DOCA and saline drinking water for 3 weeks. Both systolic blood pressure (189+/-4 versus 126+/-2 mm Hg) and aortic superoxide production (3972+/-257 versus 852+/-287, P<0. 05) were increased compared with controls. Relaxations of vascular segments to acetylcholine (ACh, 100+/-2% versus 75+/-2%, P<0.05) and the calcium ionophore A23187 (92+/-2% versus 72+/-3%, P<0.05) were also impaired in DOCA-salt. Heparin-binding superoxide dismutase (1200 U/d IV for 3 days) had no effect on blood pressure but significantly improved relaxations to ACh and A23187. Losartan (25 mg x kg(-1) x d(-1) PO) for 7 days did not correct the hypertension or endothelium-dependent vessel relaxation in DOCA-salt rats, excluding a role of a local renin/angiotensin II system. CONCLUSIONS These findings indicate that increased vascular superoxide production occurs not only in angiotensin II-induced hypertension but also in hypertension known to be associated with low-renin states. Increased superoxide production alters large-vessel endothelium-dependent vascular relaxation but does not modulate blood pressure in low-renin hypertension.


Jacc-cardiovascular Interventions | 2014

Comparison of transfemoral transcatheter aortic valve replacement performed in the catheterization laboratory (minimalist approach) versus hybrid operating room (standard approach): outcomes and cost analysis.

Vasilis Babaliaros; Chandan Devireddy; Stamatios Lerakis; Robert Leonardi; Sebastian Iturra; Kreton Mavromatis; Bradley G. Leshnower; Robert A. Guyton; Mihir Kanitkar; Patricia Keegan; Amy Simone; James Stewart; Nima Ghasemzadeh; Peter C. Block; Vinod H. Thourani

OBJECTIVES The aim of this study was to compare transfemoral transcatheter aortic valve replacement (TF TAVR) performed in a catheterization laboratory (minimalist approach [MA]) with TF TAVR performed in a hybrid operating room (standard approach [SA]). BACKGROUND A MA-TF TAVR can be performed without general anesthesia, transesophageal echocardiography, or a surgical hybrid room. The outcomes and cost of MA-TF TAVR compared with those of the SA have not been described. METHODS Patients who underwent elective, percutaneous TF TAVR using the Edwards Sapien valve (Edwards Lifesciences, Irvine, California) were studied. Baseline characteristics, outcomes, and hospital costs of MA-TF TAVR and SA-TF TAVR were compared. RESULTS A total of 142 patients were studied (MA-TF TAVR, n = 70 and SA-TF TAVR, n = 72). There were no differences in baseline comorbidities (Society of Thoracic Surgeons score, 10.6 ± 4.3 vs. 11.4 ± 5.8; p = 0.35). All procedures in the MA-TF TAVR group were successful; 1 patient was intubated. Three patients in the SA-TF TAVR group had procedure-related death. Procedure room time (150 ± 48 min vs. 218 ± 56 min, p < 0.001), total intensive care unit time (22 h vs. 28 h, p < 0.001), length of stay from procedure to discharge (3 days vs. 5 days, p < 0.001), and cost (


Arteriosclerosis, Thrombosis, and Vascular Biology | 2000

Early Effects of Arterial Hemodynamic Conditions on Human Saphenous Veins Perfused Ex Vivo

Kreton Mavromatis; Tohru Fukai; Matthew C. Tate; Naomi C. Chesler; David N. Ku; Zorina S. Galis

45,485 ± 14,397 vs.


Circulation-cardiovascular Quality and Outcomes | 2009

Quantitative Results of Baseline Angiography and Percutaneous Coronary Intervention in the COURAGE Trial

G.B. John Mancini; Eric R. Bates; David J. Maron; Pamela Hartigan; Marcin Dada; Gilbert Gosselin; William J. Kostuk; Steven P. Sedlis; Leslee J. Shaw; Daniel S. Berman; Peter B. Berger; John A. Spertus; Kreton Mavromatis; Merril L. Knudtson; Bernard R. Chaitman; Robert A. O'Rourke; William S. Weintraub; Koon K. Teo; William E. Boden

55,377 ± 22,587, p < 0.001) were significantly less in the MA-TF TAVR group. Mortality at 30 days was not significantly different in the MA-TF TAVR group (0 vs. 6%, p = 0.12) and 30-day stroke/transient ischemic attack was similar (4.3% vs. 1.4%, p = 0.35). Moderate or severe paravalvular leak and device success were similar in the MA-TF TAVR and SA-TF TAVR groups (3% vs. 5.8%, p = 0.4 and 90% vs. 88%, p = 0.79, respectively) at 30 days. At a median follow-up of 435 days, there was no significant difference in survival (MA-TF TAVR, 83% vs. SA-TF TAVR, 82%; p = 0.639). CONCLUSIONS MA-TF TAVR can be performed with minimal morbidity and mortality and equivalent effectiveness compared with SA-TF TAVR. The shorter length of stay and lower resource use with MA-TF TAVR significantly lowers hospital costs.


JAMA | 2013

Effect of progenitor cell mobilization with granulocyte-macrophage colony-stimulating factor in patients with peripheral artery disease: a randomized clinical trial.

Joseph Poole; Kreton Mavromatis; Jose Binongo; Ali Khan; Qunna Li; Mohamed Khayata; Elizabeth Rocco; Matthew Topel; Xin Zhang; Charlene Brown; Matthew A. Corriere; Jonathan R. Murrow; Salman Sher; Stephanie Clement; Khuram Ashraf; Amr Rashed; Tarek Kabbany; Robert Neuman; Alanna A. Morris; Arshad Ali; Salim Hayek; John N. Oshinski; Young-sup Yoon; Edmund K. Waller; Arshed A. Quyyumi

Exposure to the arterial hemodynamic environment is thought to be a potential trigger for the pathological remodeling of saphenous vein grafts. Using matched pairs of freshly isolated human saphenous vein, we analyzed the early effects of ex vivo hemodynamic conditions mimicking the venous (native) compared with arterial (graft) environment on the key components of vascular remodeling, ie, matrix metalloproteinase (MMP)-9 and MMP-2 and cell proliferation. Interestingly, we found that arterial conditions halved latent MMP-9 (50+/-11%, P=0.01) and MMP-2 (44+/-6%, P=0.005) levels relative to matched vein pairs maintained ex vivo under venous perfusion for up to 3 days. Immunostaining supported decreased MMP levels in the innermost area of arterially perfused veins. Either decreased synthesis or increased posttranslational processing may decrease MMP zymogen levels. Biosynthetic radiolabeling showed that arterial perfusion actually increased MMP-9 and MMP-2 production. When we then examined potential pathways for MMP zymogen processing, we found that arterial conditions did not affect the expression of MT-MMP-1, a cell-associated MMP activator, but that they significantly increased the levels of superoxide, another MMP activator, suggesting redox-dependent MMP processing. Additional experiments indicated that increased superoxide under arterial conditions was due to diminished scavenging by decreased extracellular superoxide dismutase. Arterial perfusion also stimulated cell proliferation (by 220% to 750%) in the majority of vein segments investigated. Our observations support the hypothesis that arterial hemodynamic conditions stimulate early vein graft remodeling. Furthermore, physiological arterial flow may work to prevent pathological remodeling, particularly the formation of intimal hyperplasia, through rapid inactivation of secreted MMPs and, possibly, through preferential stimulation of cell proliferation in the outer layers of the vein wall.


American Journal of Cardiology | 2009

Usefulness of Serum High-Density Lipoprotein Cholesterol Level as an Independent Predictor of One-Year Mortality After Percutaneous Coronary Interventions

Ziyad Ghazzal; Saurabh S. Dhawan; Abdul Sheikh; John S. Douglas; Emir Veledar; Kreton Mavromatis; F. Khan Pohlel; Viola Vaccarino

Background—COURAGE compared outcomes in stable coronary patients randomized to optimal medical therapy plus percutaneous coronary intervention (PCI) versus optimal medical therapy alone. Methods and Results—Angiographic data were analyzed by treatment arm, health care system (Veterans Administration, US non–Veterans Administration, Canada), and gender. Veterans Administration patients had higher prevalence of coronary artery bypass graft surgery and left ventricular ejection fraction ≤50%. Men had worse diameter stenosis of the most severe lesion, higher prevalence of prior coronary artery bypass graft surgery, lower left ventricular ejection fraction, and more 3-vessel disease that included a proximal left anterior descending lesion (P<0.0001 for all comparisons versus women). Failure to cross rate (3%) and visual angiographic success of stent procedures (97%) were similar to contemporary practice in the National Cardiovascular Data Registry. Quantitative angiographic PCI success was 93% (residual lesion <50% in-segment) and 82% (<20% in-stent), with only minor nonsignificant differences among health care systems and genders. Event rates were higher in patients with higher jeopardy scores and more severe vessel disease, but rates were similar irrespective of treatment strategy. Within the PCI plus optimal medical therapy arm, complete revascularization was associated with a trend toward lower rate of death or nonfatal myocardial infarction. Complete revascularization was similar between genders and among health care systems. Conclusions—PCI success and completeness of revascularization did not differ significantly by health care system or gender and were similar to contemporary practice. Angiographic burden of disease affected overall event rates but not response to an initial strategy of PCI plus optimal medical therapy or optimal medical therapy alone.


The New England Journal of Medicine | 2018

Five-Year Outcomes with PCI Guided by Fractional Flow Reserve

Panagiotis Xaplanteris; Stephane Fournier; Nico H.J. Pijls; William F. Fearon; Emanuele Barbato; Pim A.L. Tonino; Thomas Engstrøm; Stefan Kääb; Jan-Henk Dambrink; Gilles Rioufol; Gabor G. Toth; Zsolt Piroth; Nils Witt; Ole Fröbert; Petr Kala; Axel Linke; Nicola Jagic; Martin Mates; Kreton Mavromatis; Habib Samady; Anand Irimpen; Keith G. Oldroyd; Gianluca Campo; Martina Rothenbühler; Peter Jüni; Bernard De Bruyne

IMPORTANCE Many patients with peripheral artery disease (PAD) have walking impairment despite therapy. Experimental studies in animals demonstrate improved perfusion in ischemic hind limb after mobilization of bone marrow progenitor cells (PCs), but whether this is effective in patients with PAD is unknown. OBJECTIVE To investigate whether therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF) improves exercise capacity in patients with intermittent claudication. DESIGN, SETTING, AND PARTICIPANTS In a phase 2 double-blind, placebo-controlled study, 159 patients (median [SD] age, 64 [8] years; 87% male, 37% with diabetes) with intermittent claudication were enrolled at medical centers affiliated with Emory University in Atlanta, Georgia, between January 2010 and July 2012. INTERVENTIONS Participants were randomized (1:1) to received 4 weeks of subcutaneous injections of GM-CSF (leukine), 500 μg/day 3 times a week, or placebo. Both groups were encouraged to walk to claudication daily. MAIN OUTCOMES AND MEASURES The primary outcome was peak treadmill walking time (PWT) at 3 months. Secondary outcomes were PWT at 6 months and changes in circulating PC levels, ankle brachial index (ABI), and walking impairment questionnaire (WIQ) and 36-item Short-Form Health Survey (SF-36) scores. RESULTS Of the 159 patients randomized, 80 were assigned to the GM-CSF group. The mean (SD) PWT at 3 months increased in the GM-CSF group from 296 (151) seconds to 405 (248) seconds (mean change, 109 seconds [95% CI, 67 to 151]) and in the placebo group from 308 (161) seconds to 376 (182) seconds (change of 56 seconds [95% CI, 14 to 98]), but this difference was not significant (mean difference in change in PWT, 53 seconds [95% CI, -6 to 112], P = .08). At 3 months, compared with placebo, GM-CSF improved the physical functioning subscore of the SF-36 questionnaire by 11.4 (95% CI, 6.7 to 16.1) vs 4.8 (95% CI, -0.1 to 9.6), with a mean difference in change for GM-CSF vs placebo of 7.5 (95% CI, 1.0 to 14.0; P = .03). Similarly, the distance score of the WIQ improved by 12.5 (95% CI, 6.4 to 18.7) vs 4.8 (95% CI, -0.2 to 9.8) with GM-CSF compared with placebo (mean difference in change, 7.9 [95% CI, 0.2 to 15.7], P = .047). There were no significant differences in the ABI, WIQ distance and speed scores, claudication onset time, or mental or physical component scores of the SF-36 between the groups. CONCLUSIONS AND RELEVANCE Therapy with GM-CSF 3 times a week did not improve treadmill walking performance at the 3-month follow-up. The improvements in some secondary outcomes with GM-CSF suggest that it may warrant further study in patients with claudication. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01041417.


The Annals of Thoracic Surgery | 2015

Outcomes for Transcatheter Aortic Valve Replacement in Nonagenarians.

Michael O. Kayatta; Vinod H. Thourani; Hanna A. Jensen; Jose C. Condado; Eric L. Sarin; Patrick D. Kilgo; Chandan Devireddy; Bradley G. Leshnower; Kreton Mavromatis; Chun Li; Robert A. Guyton; James Stewart; Amy Simone; Patricia Keegan; Peter C. Block; Stamatios Lerakis; Vasilis Babaliaros

Low levels of high-density lipoprotein (HDL) cholesterol are a marker of coronary artery disease progression and are associated with cardiovascular events. However, whether low HDL cholesterol is a useful prognostic indicator after percutaneous coronary intervention (PCI) is not known. In a sample of 4,088 patients who underwent PCI we evaluated 1-year mortality and repeat revascularization as a function of baseline HDL levels classified into approximate quartiles of very low (<35 mg/dl), low (35 to 40 mg/dl), medium (41 to 47 mg/dl) and high (48 to 120 mg/dl) HDL cholesterol. Decreasing levels of HDL cholesterol were associated with younger age, male gender, smoking, diabetes mellitus, and a history of bypass surgery (p <0.0001 for all). One-year mortality and coronary revascularization were significantly higher in the very low HDL cholesterol group compared with the other groups (very low HDL cholesterol 6.5% and 25.4%, respectively; low HDL cholesterol 3.1% and 20.8%; medium HDL cholesterol 4.3% and 22.7%; high HDL cholesterol 3.1% and 20.6%, p = 0.0001 and p = 0.007). One-year mortality was significantly higher in men with an HDL cholesterol level <33 mg/dL and in women with an HDL cholesterol level <38 mg/dL. In multivariable analysis, very low HDL was associated with nearly twofold the risk of death after adjusting for other independent predictors of outcome. In conclusion, in patients with coronary artery disease undergoing PCI, a baseline HDL cholesterol level <35 mg/dl is an important prognostic indicator. Baseline HDL cholesterol levels <33 mg/dl for men and <38 mg/dl were associated with higher one-year mortality after PCI.

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