Nikolaos Patsouras

Weight loss after bariatric surgery improves aortic elastic properties and left ventricular function in individuals with morbid obesity: a 3-year follow-up study.

Objective To investigate whether weight loss after bariatric surgery (gastric bypass) is associated with changes in aortic function (an important determinant of left ventricular function) and in left ventricular function, in morbidly obese individuals 3 and 36 months after surgery. Methods We used echocardiography to evaluate 60 obese individuals [body mass index (BMI) > 40 kg/m2] who underwent surgery and 20 obese individuals who neither underwent surgery nor lost weight, at baseline and at 3 and 36 months of follow-up, and 40 lean individuals (BMI < 25 kg/m2) of similar age, sex and risk factors, at baseline. We measured aortic strain, distensibility, stiffness index, pressure–strain modulus and Doppler indices of left ventricular diastolic dysfunction (ratio of peak early to peak atrial flow velocities, isovolumic relaxation time and deceleration time). Results Baseline aortic function and Doppler diastolic indices were impaired in obese individuals compared with those who were lean (P < 0.05). During 3 and 36 months of follow-up, BMI and left ventricular diastolic diameter, volume, mass and wall thickness were reduced, and indices of aortic function and left ventricular diastolic function were normalized, in obese individuals after surgery [aortic distensibility (cm2 × dyn−1 × 10−6): 1.9 before surgery, 3.4 at 3 months after surgery and 4.3 at 3 years after surgery, compared with 3.36 in lean controls; P < 0.01], but not in those who did not lose weight. The reduction in BMI after surgery was related to the concomitant improvement in indices of aortic function (P < 0.01) and isovolumic relaxation time (P < 0.05) after adjustment for age, sex and concomitant reduction in blood pressure, lipids and glucose concentrations. Conclusion Weight reduction after bariatric surgery normalizes aortic function, reduces left ventricular hypertrophy and, thus, improves left ventricular diastolic function in morbidly obese individuals over a 3-year period of follow-up.

Autonomic patterns preceding and following accelerated idioventricular rhythm in acute myocardial infarction.

Introduction: We have investigated the potential relationship between cardiac autonomic activity and accelerated idioventricular rhythm (AIVR) in response to reperfusion in the setting of an acute myocardial infarction (AMI) through spectral analysis of heart rate variability (HRV). Methods and Results: We studied 16 patients with AMI who developed spontaneous sustained AIVR after initiation of intravenous thrombolysis. Sympathovagal interactions were evaluated by analysis of the low- (LF) and high-frequency (HF) spectral components of HRV for each 5-min interval over the 30-min periods preceding and following AIVR. The occurrence of AIVR was related to the ST-segment elevation resolution and the angiographic evidence of restored coronary flow to assess timely reperfusion and sustained coronary artery patency. The analysis of spectral components over time revealed combined responses of both autonomic limbs preceding and following AIVR, which were not followed by corresponding changes in heart rate. Ten minutes before AIVR, there was a characteristic continuous increase in LF, in the setting of a concomitant withdrawal of HF, suggestive of a progressive sympathetic predominance. After the end of AIVR, the opposite pattern was found with an increased HF and decreased LF, indicative of parasympathetic rebound overactivity. All patients showed signs of fast reperfusion and complete restoration of coronary flow. Conclusion: Our results indicate that reperfusion-induced AIVR is modulated by sympathetic stimulatory effects, whereas a counterregulatory vagal response seems to exert a profound effect upon its suppression. Clinically, the occurrence of early sustained AIVR appears to offer reliable information about both timely reperfusion and sustained and effective coronary artery patency.

Usefulness of Reperfusion Ventricular Arrhythmias in Non-invasive Prediction of Early Reperfusion and Sustained Coronary Artery Patency in Acute Myocardial Infarction

AbstractBackground: Established tenets of occurrence of reperfusion ventricular arrhythmias in acute myocardial infarction (AMI) do not provide insight into the timing of achieving reperfusion or whether coronary artery patency is sustained. We assessed the significance of ventricular arrhythmias in the non-invasive prediction of timely reperfusion and sustained restoration of coronary patency after thrombolysis in patients with AMI.nMethods: 24-hour Holter monitors were placed in 163 patients with an AMI before administration of thrombolytic therapy. Patients were classified into 3 groups of early (within 2 hours) or late reperfusion, or no-reperfusion, according with clinical and continuous ST-segment electrocardiographic criteria. Ventricular fibrillation, ventricular tachycardia (VT) and accelerated idioventricular rhythm (AIVR) were also categorized as having occurred early (within the first 2 hours) or late (after the first 2-hour period). Angiographic confirmation of coronary patency was determined 2 to 6 days after AMI.nResults: Early reperfusion was predicted by early sustained AIVR in 86% of patients and early non-sustained AIVR in 62.5% of patients, with sensitivity 38% and 77%, and specificity 96% and 69%, respectively; p<0.0001. Late non-sustained AIVR was commonly seen in early and late reperfused patients (92–97%) as well as in non-reperfused patients (74%). Sustained coronary patency was predicted by early sustained AIVR in 93% of patients, as well as by early non-sustained AIVR in 86% of patients and late non-sustained AIVR in 79% of patients, with sensitivity 22%, 55% and 94%, and specificity 95%, 71% and 18%, respectively; p<0.05.nConclusion: Only the occurrence of sustained AIVR, and probably early non-sustained AIVR convey useful information about both early reperfusion and sustained coronary artery patency. The absence of AIVR does not preclude successful thrombolysis.nAbbreviated Abstract. This study investigated the prognostic value of reperfusion ventricular arrhythmias in non-invasive prediction of early reperfusion (at the 2-hour “cutoff-point” after thrombolysis) and sustained restoration of coronary patency in patients with acute myocardial infarction. Only sustained accelerated idioventricular rhythm (AIVR) and early episodes of non-sustained AIVR could be used as surrogate markers of early reperfusion and sustained coronary patency. Non-sustained AIVR does not have any prognostic significance occurring irrespective of reperfusion status.

Lack of Association Between the Cholesteryl Ester Transfer Protein Gene—TaqIB Polymorphism and Coronary Restenosis Following Percutaneous Transluminal Coronary Angioplasty and Stenting: A Pilot Study

Background: The most widely studied variation at the cholesteryl ester transfer protein (CETP) gene locus is a silent base change called the Thermobius aquaticus IB (TaqIB) polymorphism. TaqIB has been shown to affect levels/activity of CETP, plasma levels of high-density lipoprotein cholesterol (HDL-C), and to contribute to the risk of developing atherosclerosis and coronary heart disease (CHD). Ongoing studies are investigating possible associations between CETP gene polymorphisms and the development of coronary restenosis following percutaneous transluminal coronary angioplasty (PTCA) and stenting. Methods and Results: The primary objective of the present study was to investigate the frequency of TaqIB-polymorphism, and a possible association with post-PTCA coronary restenosis, in 204 Greek patients who had undergone PTCA and stenting. As a secondary objective, the analysis was extended to explore possible interacting or additive effects by various CHD risk factors, and a deletion in the α2B-adrenergic receptor gene. The frequency of TaqIB was 54%, similar to the frequency of the polymorphism in a group of 35 healthy controls. Conclusions: The results from this study do not indicate that the TaqIB variation at the CETP gene locus is a significant predictor for assessing the risk of developing coronary restenosis following PTCA and stenting. This result was not affected when considering any one of the additionally studied factors.

Assessment of absolute Tc-99m tetrofosmin retention in the myocardium as an index of myocardial blood flow and coronary flow reserve by gated-SPECT/CT: a feasibility study.

ObjectiveEstimation of myocardial blood flow (MBF) and coronary flow reserve (CFR) by SPECT myocardial perfusion imaging (MPI) remains challenging. Our aim was to approximate MBF and CFR by quantifying the absolute Tc-99m tetrofosmin retention in the myocardium via gated-SPECT/CT MPI.MethodsTracer retention was calculated on the basis of the microsphere kinetic model and served as an index of MBF at stress and rest (sMBFi, rMBFi). CFR was given by the sMBFi/rMBFi ratio. A planar first-pass acquisition during dipyridamole stress and at rest provided the data for tracer input determination. The input was represented by the integral of a gamma variate fitted on the time-activity curve of the left ventricle. Gated-SPECT/CT was performed 1xa0h post tracer injection and myocardial activity was measured in attenuation-corrected transaxial slices by a threshold VOI. The input was also compensated for tissue attenuation by measuring the distance from the centre of the left ventricle to the body surface on fused SPECT/CT slices. Input and uptake results were adjusted for planar-SPECT counting geometry differences by the aid of a phantom experiment. Thirty-nine subjects with low probability of coronary artery disease (CAD), age lower than 75xa0years and normal MPI (control group) were compared with 57 patients with documented CAD (CAD group).ResultsCFR and sMBFi values of CAD patients (1.39xa0±xa00.37 and 1.42xa0±xa00.35xa0ml/min/g) were considerably lower (pxa0<xa00.0001) than controls (1.68xa0±xa00.25 and 1.72xa0±xa00.37xa0ml/min/g). Significant difference in CFR (pxa0=xa00.03) was also noted between CAD patients with normal MPI (1.48xa0±xa00.38) and controls. However, sMBFi managed to discriminate certain CAD subgroups (normal MPI/ischemia/scar/scar and ischemia) more efficiently than CFR. Maximum heart rate-blood pressure product (RPP) during stress was an independent predictor of sMBFi and CFR. The other independent CFR correlates were resting RPP and diabetes mellitus, while sMBFi was associated with age, sex, smoking, and stress perfusion defects.ConclusionsDespite the low myocardial extraction fraction of Tc-99m tetrofosmin, an approximation of MBF and CFR is feasible with gated-SPECT/CT MPI. These flow indices together were able to discriminate CAD patients from controls and stratify different patient subgroups.

ST-segment depression during vasodilator stress is of minor clinical importance in women with normal myocardial perfusion imaging and low or intermediate risk of coronary artery disease

PurposeThe prognostic value of electrocardiographic (ECG) ST-segment depression during vasodilator stress testing in patients with normal myocardial perfusion scintigraphy (MPS) is based on retrospective studies with controversial results. Moreover, the true incidence of obstructive coronary artery disease (CAD) in these patients is unknown.MethodsDuring a 33-month period, all consecutive patients referred for MPS were prospectively evaluated for interpretable ST-segment depressionu2009≥u20091xa0mm during vasodilator stress testing. Of 1,687 patients with normal MPS and without known CAD, 109 (100 women) aged 65.2u2009±u20099.2 years demonstrated ST-segment shifts and formed the ECG-positive group. The pretest probability of CAD was low in 56%, intermediate in 39% and high in 5%. They were advised to proceed to coronary angiography. An equal number of patients with normal MPS and no ECG abnormalities matched for CAD predisposing factors comprised the control group. Follow-up of both groups was accomplished through a telephone interview.ResultsFifty-two patients from the ECG-positive group (48%) consented to coronary angiography. Six (11.5%) had obstructive CAD (≥50% lumen stenosis), one with left main artery disease, while three required revascularization. Follow-up was complete in 99 ECG-positive patients for a period of 20.6u2009±u20098.9xa0months. One hard event (non-fatal myocardial infarction) and one soft event (revascularization) were observed. No event was recorded in the control group.ConclusionIn patients with low-intermediate risk of CAD, “ischaemic” ECG changes during vasodilator stress combined with normal MPS are encountered mostly in women and are associated with a low prevalence of significant CAD and a low cardiac event rate.

Tc-99m Depreotide SPECT/CT depicts myocardial involvement in a case of thrombotic thrombocytopenic purpura.

We report a case of thrombotic thrombocytopenic purpura (TTP) with cardiac involvement, imaged with Tc-99m depreotide. A 56-year-old man presented with fever, hematuria, and chest pain. Laboratory findings (angiopathic hemolytic anemia, thrombocytopenia, and uremia) were suggestive of TTP. Cardiac enzymes were elevated and diffuse left ventricular hypokinesis was demonstrated by echocardiography. Serum rheumatologic and virologic analysis were negative. A Tc-99m depreotide SPECT/CT study showed diffuse uptake in the myocardium, indicating inflammatory reaction to thrombotic/hemorrhagic myocardial damage. We suggest that Tc-99m depreotide imaging may reveal myocardial involvement in TTP; this could prompt further investigation for potential applications in myocarditis of other etiologies.

Lack of association between α2B-adrenergic receptor polymorphism and risk of restenosis following coronary angioplasty and stent implantation – preliminary report

Abstract Background: A genetic association/prospective follow-up study was conducted to investigate whether genetic variation of the α2B-adrenergic receptor gene was associated with the risk of restenosis in 96 Greek coronary artery disease patients undergoing coronary angioplasty and stent implantation. Methods: For comparison of genotype frequency, a control group of 83 asymptomatic individuals was also studied. The end-point of the current study was the incidence of restenosis at 7 months of clinical follow-up. Results: The majority of patients (70/96) had the insertion/insertion genotype, fewer patients (23/96) had the insertion/deletion genotype and only 3/96 had the deletion/deletion genotype; overall the frequency distribution was not different from that of the control subjects. Restenosis occurred in 15 of the 96 patients. Conclusions: In the population studied, α2B-adrenoreceptor polymorphisms were not found to predispose patients to an increased incidence of restenosis. Nevertheless, these findings should be considered as preliminary, taking into account the small number of patients that were studied and the rarity of the deletion/deletion genotype. Clin Chem Lab Med 2006;44:807–12.

How Innocent is the Restenosis of the Infarct-related Coronary Artery After Successful Initial Recanalization?

The present case report describes a patient who sustained an acute inferior wall myocardial infarction, but initially remained clinically stable, then he underwent a successful coronary angioplasty and stenting procedure of a totally occluded right coronary artery, subsequently developing a dramatic clinical course with cardiogenic shock and cardiac arrest due to acute stent thrombosis which was successfully managed with repeat coronary angioplasty. We attributed this discrepant clinical manifestation of acute coronary occlusion to coronary collaterals, initially being present and then disappearing following the recanalization procedure, as being responsible for the dramatic clinical picture following the stent thrombosis.Aim: The purpose of this investigation was to collect data on the appropriate nursing care to patients supported with an intra-aortic balloon pump (IABP).Patients: All 39 patients who were supported with an IABP during the year 2006 (23 men ??? 16 women) took part in this investigation. They received nursing and medical care in the Intensive Care Cardiovascular Unit (ICCU) of Evagelismos General Hospital of Athens.Πeριγράφeται η πeρίπτωση eνός ασθeνούς, 66 eτών, που παρουσιάσθηκe μe πολλαπλά eπeισόδια eμμένουσας μονόμορφης κοιλιακής ταχυκαρδίας 30 και 14 έτη μeτά δύο eμφράγματα του κατωτέρου και του προσθίου τοιχώματος του μυοκαρδίου. Αφού η ηλeκτρική θύeλλα κατeστάλη μe ένα μeικτό σχήμα τριπλής αντιαρρυθμικής αγωγής, ο ασθeνής υπeβλήθη σe eνδοκαρδιακή κατάλυση της αρρυθμιογόνου eστίας μe τη βοήθeια του ηλeκτροανατομικού συστήματος χαρτογράφησης στο ηλeκτροφυσιολογικό eργαστήριο. Ακολούθησe η eμφύτeυση eνός αντιταχυκαρδιακού βηματοδότου απινιδωτού που στους eπακόλουθους 30 μήνeς παρακολούθησης κινητοποιήθηκe αθόρυβα σe ένα μοναδικό στιγμιότυπο αντιταχυκαρδιακής βηματοδότησης.Ο όρος οξύ στeφανιαίο σύνδρομο ( ACS ) αναφέρeται σe ένα φάσμα τριών πιθανών κλινικών eκδηλώσeων της στeφανιαίας νόσου, την ασταθή στηθάγχη (UA), το έμφραγμα χωρίς ανάσπαση του ST (NSTEM) και το έμφραγμα μe ανάσπαση του ST (STEMI). Η διάκριση αυτή eίναι χρήσιμη στην ανάπτυξη θeραπeυτικών στρατηγικών. Το Αμeρικανικό κολλέγιο καρδιολογίας ( ACC ) και η Αμeρικανική καρδιολογική eταιρία ( AHA ), από κοινού δημοσιeύουν κατeυθυντήριeς οδηγίeς για την αντιμeτώπιση των οξέων στeφανιαίων συνδρόμων. Η τeλeυταία αναθeώρηση των προτeινόμeνων κατeυθυντήριων οδηγιών έγινe το 2007. Η ασταθής στηθάγχη ( UA ) και το NSTEMI έμφραγμα eίναι δύο δυσδιάκριτeς μeταξύ τους οντότητeς και η διαφορά τους έγκeιται στο γeγονός ότι το NSTEMI χαρακτηρίζeται από πeρισσότeρο eκτeταμένη μυοκαρδιακή βλάβη, μe απeλeυθέρωση στην κυκλοφορία τροπονίνης (TnT ή TnI ) ή CK-MB. Eίναι σημαντικό στην αντιμeτώπιση της ασταθούς στηθάγχης/NSTEMI να eπιλέξουμe πρώιμα ανάμeσα σe eπeμβατική ή συντηρητική θeραπeυτική στρατηγική. Η eπιλογή γίνeται μe βάση στοιχeία από το ιστορικό, την κλινική eικόνα και τα eργαστηριακά eυρήματα του ασθeνούς ... (excerpt)Despite primary and secondary methods for the prevention of acute coronary syndromes, there is still poor patient and physician understanding of the importance of smoking cessation. Cardiovascular risk decreases significantly after smoking cessation, however, there is a paucity of counseling programs regarding this issue after hospitalization. Such programs have proved to be cost effective and should be provided as standard care.