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Dive into the research topics where Konstantinos Petidis is active.

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Featured researches published by Konstantinos Petidis.


The Lancet | 2008

Prevalence of primary hyperaldosteronism in resistant hypertension: a retrospective observational study.

Stella Douma; Konstantinos Petidis; Michael Doumas; Panagiota Papaefthimiou; Areti Triantafyllou; Niki Kartali; Nikolaos Papadopoulos; Konstantinos Vogiatzis; Chrysanthos Zamboulis

BACKGROUND Results of several studies published since 1999 suggest that primary hyperaldosteronism (also known as Conns syndrome) affects more than 10% of people with hypertension; however, such a high prevalence has also been disputed. Experts generally agree that resistant hypertension has the highest prevalence of primary hyperaldosteronism, on the basis of small studies. We aimed to assess the prevalence of primary hyperaldosteronism in a large group of patients with resistant hypertension. METHODS Patients with resistant hypertension (blood pressure >140/90 mm Hg despite a three drug regimen, including a diuretic) who attended our outpatient clinic were assessed for primary hyperaldosteronism. Serum aldosterone and plasma renin activity were determined and their ratio was calculated. Patients with a positive test (ratio >65.16 and aldosterone concentrations >416 pmol/L) underwent salt suppression tests with intravenous saline and fludrocortisone. Diagnosis of primary hyperaldosteronism was further confirmed by the response to treatment with spironolactone. FINDINGS Over 20 years, we studied 1616 patients with resistant hypertension. 338 patients (20.9%) had a ratio of more than 65.16 and aldosterone concentrations of more than 416 pmol/L. On the basis of salt suppression tests, 182 (11.3%) patients had primary hyperaldosteronism, and response to spironolactone treatment further confirmed this diagnosis. Hypokalaemia was seen only in 83 patients with primary hyperaldosteronism (45.6%). INTERPRETATION Although the prevalence of primary hyperaldosteronism in patients with resistant hypertension was high, it was substantially lower than previously reported. On the basis of this finding, we could assume that the prevalence of primary hyperaldosteronism in the general unselected hypertensive population is much lower than currently reported. Thus, the notion of an epidemic of primary hyperaldosteronism is not supported.


Jcr-journal of Clinical Rheumatology | 2012

Cardiovascular risk in rheumatoid arthritis: pathogenesis, diagnosis, and management.

Eugenia Gkaliagkousi; Eleni Gavriilaki; Michael Doumas; Konstantinos Petidis; Spyros Aslanidis; Douma Stella

Abstract Rheumatoid arthritis is characterized by early and accelerated atherosclerosis leading to increased cardiovascular morbidity and mortality. Beyond traditional cardiovascular risk factors, several pathogenetic mechanisms have been proposed, including emerging inflammatory and autoimmune mechanisms. Inflammatory stimuli are now believed to cause vascular damage, which can be estimated by well-established noninvasive techniques. Carotid intima-media thickness, pulse-wave velocity and flow-mediated dilatation, markers of subclinical atherosclerosis, arterial stiffness, and endothelial function, respectively, have been recently used to detect vascular dysfunction in the wide spectrum of autoimmune diseases. The role of anti–tumor necrosis factor &agr; and novel biologic agents remains unclear, although early control of the inflammatory process seems crucial for reducing cardiovascular risk. Considering the importance of cardiovascular risk management, further well-designed studies are warranted to clarify the potential benefits and harms of anti-inflammatory treatment.


BMC Cardiovascular Disorders | 2008

The interaction of vasoactive substances during exercise modulates platelet aggregation in hypertension and coronary artery disease.

Konstantinos Petidis; Stella Douma; Michael Doumas; Ilias Basagiannis; Konstantinos Vogiatzis; Chrysanthos Zamboulis

BackgroundAcute vigorous exercise, associated with increased release of plasma catecholamines, transiently increases the risk of primary cardiac arrest. We tested the effect of acute submaximal exercise on vasoactive substances and their combined result on platelet function.MethodsHealthy volunteers, hypertensive patients and patients with coronary artery disease (CAD) performed a modified treadmill exercise test. We determined plasma catecholamines, thromboxane A2, prostacyclin, endothelin-1 and platelet aggregation induced by adenosine diphosphate (ADP) and collagen at rest and during exercise.ResultsOur results during exercise showed a) platelet activation (increased thromboxane B2, TXB2), b) increased prostacyclin release from endothelium and c) decreased platelet aggregation in all groups, significantly more in healthy volunteers than in patients with CAD (with hypertensives lying in between these two groups).ConclusionDespite the pronounced activation of Sympathetic Nervous System (SNS) and increased TXB2 levels during acute exercise platelet aggregation decreases, possibly to counterbalance the prothrombotic state. Since this effect seems to be mediated by the normal endothelium (through prostacyclin and nitric oxide), in conditions characterized by endothelial dysfunction (hypertension, CAD) reduced platelet aggregation is attenuated, thus posing such patients in increased risk for thrombotic complications.


International Journal of Hypertension | 2011

Benefits from Treatment and Control of Patients with Resistant Hypertension

Michael Doumas; Vasilios Papademetriou; Stella Douma; Charles Faselis; Konstantinos Tsioufis; Eugene Gkaliagkousi; Konstantinos Petidis; Chrysanthos Zamboulis

Resistant hypertension is commonly found in everyday clinical practice. However, the risks of resistant hypertension, as well as the benefits of treatment and control of blood pressure in patients with resistant hypertension remain vaguely clarified. Data from small clinical studies and observational cohorts suggest that patients with resistant hypertension are at increased cardiovascular risk, while control of blood pressure offers substantial benefits. It has to be noted however that data from appropriate large randomized studies are missing, and resistant hypertension remains remarkably understudied. Resistant hypertension has attracted significant scientific interest lately, as new therapeutic modalities become available. The interventional management of resistant hypertension either by carotid baroreceptor stimulation or renal sympathetic denervation is currently under investigation with promising preliminary results. This review presents available evidence regarding the benefits of treatment and control of blood pressure in patients with resistant hypertension and offers a critical evaluation of existing data in this field.


Hypertension | 2011

Renal Sympathetic Denervation: Renal Function Concerns

Konstantinos Petidis; Panagiota Anyfanti; Michael Doumas

To the Editor: We have read the report of the Simplicity HTN-1 investigators on the 2-year durability of blood pressure reduction induced by catheter-based renal sympathetic denervation with great excitement1 because it represents a promising approach for treatment of resistant hypertension.2 However, several concerns arise that require clarification. First, the effect of renal sympathetic denervation on renal function should be dealt with the greatest circumspection. In the 10 patients with available 2-year estimated glomerular filtration rate data, a decrease by −16.0 mL/min per 1.73 m2 was noticed, which was as well observed to a lesser but significant degree (−7.8 mL/min per 1.73 m2) in 5 of those …


American Journal of Hypertension | 2014

Association between retinal vessel caliber and arterial stiffness in a population comprised of normotensive to early-stage hypertensive individuals.

Areti Triantafyllou; Panagiota Anyfanti; Eleni Gavriilaki; Xenophon Zabulis; Eugenia Gkaliagkousi; Konstantinos Petidis; George Triantafyllou; Vasileios Gkolias; Athina Pyrpasopoulou; Stella Douma

BACKGROUND Although impairment of the micro- and macrocirculation is considered inherent to sustained hypertension, there is a substantial lack of studies investigating whether an association exists between micro- and macrovascular damage, especially in early-stage hypertension. METHODS We studied a meticulously selected population, free of diabetes and cardiovascular disease, of 223 individuals: 137 never-treated, newly diagnosed patients with recent onset of hypertension and 86 normotensive individuals. Nonmydriatic retinal photography was used to assess retinal microvascular diameters, including central retinal arteriolar (CRAE) and venular equivalent and arteriovenous ratio (AVR). Arterial stiffness was evaluated by measurement of pulse wave velocity (PWV) and aortic augmentation index (AIx). RESULTS Compared with normotensive subjects, hypertensive patients exhibited significantly increased PWV (8.1 vs. 7.1 m/sec; P < 0.001) and AIx (23.86% vs. 18.8%; P = 0.01) and decreased CRAE (86.47 vs. 91.44 μm; P = 0.001) and AVR (0.74 vs. 0.78; P = 0.007). A significant inverse association was demonstrated between PWV and CRAE (r = -0.205; P = 0.002), which remained significant after multivariable analysis. Likewise, CRAE (P = 0.04) and AVR (P = 0.02) were independent predictors of AIx. CONCLUSIONS This study shows for the first time an association between quantitatively assessed retinal abnormalities and increased arterial stiffness in a sample of early-stage hypertensive and normotensive individuals, suggesting that micro- and macrocirculation impairment in hypertension is a dynamic, mutual, interdependent process present from its very early stages. Given the predictive value of both retinal arteriolar narrowing and arterial stiffness in terms of cardiovascular mortality and morbidity, identification of combined micro- and macrovascular damage might be helpful in cardiovascular risk stratification of hypertensive patients.


American Journal of Hypertension | 2013

Divergent Retinal Vascular Abnormalities in Normotensive Persons and Patients With Never-Treated, Masked, White Coat Hypertension

Areti Triantafyllou; Michael Doumas; Panagiota Anyfanti; Eugenia Gkaliagkousi; Xenophon Zabulis; Konstantinos Petidis; Eleni Gavriilaki; Polykarpos Karamaounas; Vasileios Gkolias; Athina Pyrpasopoulou; Anna-Bettina Haidich; Chrysanthos Zamboulis; Stella Douma

BACKGROUND Hypertensive patients with retinal arteriolar abnormalities are at increased risk for cardiovascular events. However, the extent of retinal microvascular changes in naïve, never-treated patients with hypertension of short duration has not been established. In addition to this, the lack of relevant data about other phenotypes of hypertension (masked and white-coat hypertension) determined by ambulatory blood-pressure measurement (ABPM) is notable, despite their relationship to increased cardiovascular risk mediated by underlying target-organ and vascular damage. METHODS We conducted a study in which nonmydriatic retinal photography was used to assess central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) diameters and the retinal arteriovenus ratio (AVR) in a group of 103 individuals with never-treated hypertension of recent (< 1 year) appearance, 28 individuals with masked and 20 with white-coat hypertension, and 50 normotensive individuals, as appropriately classified by ABPM. RESULTS Patients with sustained and masked hypertension had narrower values of CRAE than did normotensive individuals (86.7±10.1 and 87.6±9.2 vs. 94.8±10.6, P < 0.001 and P = 0.02, respectively). The AVR was lower in patients with sustained hypertension (0.736±0.102), masked hypertension (0.716±0.123), and white-coat hypertension (0.739±0.127) than in normotensive subjects (0.820±0.095), P < 0.001, P < 0.001, and P = 0.03, respectively. Both AVR and CRAE were negatively associated with mean systolic and diastolic daytime, nighttime, and 24-hour blood pressures, even after adjustment for other factors. CONCLUSIONS Subtle retinal microvascular signs of pathology are observed in hypertensive patients at early stages of hypertension and in patients with both masked and white coat hypertension. These changes may be indicative or may mediate the differences in cardiovascular mortality in persons with masked and white-coat hypertension, and relevant information about this can be easily accessed with retinal photography.


American Journal of Hypertension | 2014

Platelet Activation in Essential Hypertension During Exercise: Pre- and Post-Treatment Changes With an Angiotensin II Receptor Blocker

Eugenia Gkaliagkousi; Eleni Gavriilaki; Efi Yiannaki; Dimitra Markala; Nikolaos Papadopoulos; Areti Triantafyllou; Panagiota Anyfanti; Konstantinos Petidis; Vasileia Garypidou; Michael Doumas; Albert Ferro; Stella Douma

BACKGROUND Acute exercise may exert deleterious effects on the cardiovascular system through a variety of pathophysiological mechanisms, including increased platelet activation. However, the degree of exercise-induced platelet activation in untreated hypertensive (UH) individuals as compared with normotensive (NT) individuals has yet to be established. Furthermore, the effect of antihypertensive treatment on exercise-induced platelet activation in essential hypertension (EH) remains unknown. METHODS Study 1 consisted of 30 UH and 15 NT subjects. UH subjects who received treatment were included in study 2 and were followed-up after a 3-month treatment period with an angiotensin II receptor blocker (ARB; valsartan). Circulating monocyte-platelet aggregates (MPA) and platelet P-selectin were measured as platelet activation markers at baseline, immediately after a treadmill exercise test, and 10, 30, and 90 minutes later. RESULTS Maximal platelet activation was observed at 10 minutes after peak exercise in both groups. In UH subjects, MPA levels remained increased at 30 minutes after peak exercise, despite BP fall to baseline levels. MPA levels were significantly higher in UH subjects than NT subjects at maximal exercise and at 10 and 30 minutes of recovery. Post-treatment MPA levels increased significantly only at 10 minutes into recovery and were similar to those of NT subjects. CONCLUSIONS Acute high-intensity exercise exaggerates platelet activation in untreated patients with EH compared with NT individuals. Angiotensin II receptor blockade with adequate BP control greatly improves exercise-induced platelet activation in EH. Further studies are needed to clarify whether this phenomenon depends purely on BP lowering or benefits also from the pleiotropic effects of ARBs.


Journal of Andrology | 2013

The impact of frequently encountered cardiovascular risk factors on sexual dysfunction in rheumatic disorders

Panagiota Anyfanti; Athina Pyrpasopoulou; Areti Triantafyllou; Michael Doumas; Eleni Gavriilaki; Georgios Triantafyllou; Eugenia Gkaliagkousi; Sofia Chatzimichailidou; Konstantinos Petidis; P.-A. Avagianou; Chrysanthos Zamboulis; Spyros Aslanidis; Stella Douma

Traditional cardiovascular risk factors have been acknowledged as major contributors to sexual dysfunction in the general population. The purpose of this study was to explore their impact on sexual function in rheumatologic patients. A total of 557 consecutive rheumatologic patients, 449 females and 108 males, had their sexual function evaluated with the Female Sexual Functioning Index (FSFI) and the International Index of Erectile Function (IIEF) questionnaire respectively. Personal data regarding presence of cardiovascular risk factors were collected and analysed in association with the FSFI and IIEF scores. Mean age of the participants was 54.1 ± 14.1 years, mean body mass index was 27.5 ± 5.29 and mean systolic and diastolic blood pressure was 130.5 ± 19.82 and 79.5 ± 10.51 mmHg respectively. Hypertension was present in 39% of the participants, diabetes mellitus in 10.2%, dyslipidaemia in 33.6% and history of cardiovascular events in 8.6%, whereas smoking was recorded by 28.4% and alcohol consumption by 7.4%. Sexual dysfunction affected 68.6% of our study population (73.5% of females and 48.1% of males, p < 0.001). Logistic regression analysis revealed that age was the only factor associated with a significantly higher prevalence of sexual dysfunction (p < 0.001 for both genders, p = 0.013 in males and p < 0.001 in females). Increased age was identified as the only independent predictor of sexual dysfunction in our population. Apart from age, traditional cardiovascular risk factors failed to explain the increased prevalence of sexual dysfunction in these patients. Other contributing factors (physical and/or psychological) might account for the increased occurrence of sexual dysfunction in rheumatic disorders.


European Journal of Clinical Investigation | 2009

Neurofibromatosis type 1: should we screen for other genetic syndromes? A case report of co‐existence with multiple endocrine neoplasia 2A

E. Gkaliagkousi; Konstantinos Petidis; P. Semertzidis; Michael Doumas; Chrysanthos Zamboulis; Hartmut P. H. Neumann; Stella Douma

Background  NF 1 is a genetic disorder with an autosomal dominant pattern of inheritence. It is associated with neoplastic disorders mainly derived from the neural seath. However, the co‐existence of NF1 with the full spectrum of MEN 2A has rarely been reported. The aim of the study was to investigate the presence of secondary neoplasias in a patient with diagnosed NF1, and in particular the presence of hyperparathyroidism and the possible co‐existence with another pheochromocytoma‐related syndrome.

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Stella Douma

Aristotle University of Thessaloniki

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Michael Doumas

George Washington University

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Chrysanthos Zamboulis

Aristotle University of Thessaloniki

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Areti Triantafyllou

Aristotle University of Thessaloniki

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Panagiota Anyfanti

Aristotle University of Thessaloniki

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Eleni Gavriilaki

Aristotle University of Thessaloniki

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Eugenia Gkaliagkousi

Aristotle University of Thessaloniki

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Athina Pyrpasopoulou

Aristotle University of Thessaloniki

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Konstantinos Imprialos

Aristotle University of Thessaloniki

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Konstantinos Stavropoulos

Aristotle University of Thessaloniki

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