Vruyr Balian

Azienda ospedaliera di Busto Arsizio, Ansizio, Lombardy, Italy

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Publications (14)48.57 Total impact

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    ABSTRACT: OBJECTIVES This study aimed to determine whether the intracoronary electrograms (IC-EGMs) recorded using a standard percutaneous coronary intervention guidewire could provide myocardial viability information. BACKGROUND The revascularization of dysfunctional but viable myocardium may confer prognostic benefits compared with medical therapy in patients with post-ischemic heart failure. However, knowledge of myocardial viability is often unavailable at the time of the procedure. METHODS The peak-to-peak voltage of 317 IC-EGMs recordings from 25 patients with a previous myocardial infarction and systolic dysfunction were matched with corresponding delayed-enhancement magnetic resonance imaging sites using a 17-segment model of the left ventricle. RESULTS Sixty-seven recordings were obtained from segments classified as complete scar on delayed-enhancement magnetic resonance imaging (group A), 162 from partially viable segments (group B), and 88 from fully viable segments (group C). Three high-pass (HP) filters (0.5, 30, and 100 Hz) were applied to the signals to modulate their spatial resolution. For all filters, the peak-to-peak voltage significantly decreased from group C to group B to group A (p < 0.001 for all comparisons). When receiver-operating characteristic analysis was used to compare nonviable (group A) with viable (group B + C) segments, the optimal discriminating voltages were 4.6, 2.2, and 0.78 mV for, respectively, HP-0.5, HP-30, and HP-100 filters, with a sensitivity of 92%, 94%, and 99% and a specificity of 70%, 79%, and 69%. CONCLUSIONS The amplitude of the IC-EGMs discriminates viable from nonviable left ventricular segments. Because this technique is simple and inexpensive and provides real-time results, it is potentially useful to aid decision making in the catheterization laboratory. c 2014 by the American College of Cardiology Foundation.
    JACC Cardiovascular Interventions 08/2014; 7(9). DOI:10.1016/j.jcin.2014.04.009 · 7.44 Impact Factor
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    ABSTRACT: Percutaneous coronary interventions (PCIs) are increasingly being performed worldwide to treat patients with coronary artery disease. However, studies on the influence of ethnicity on clinical outcomes after PCI are scarce. In our current analysis, we evaluate the differences in baseline clinical, angiographic and procedural characteristics, and 12-month clinical outcomes in patients undergoing nonurgent PCI in Western Europe and in Asia. We analyzed all patients enrolled in the worldwide e-HEALING (electronic Healthy Endothelial Accelerated Lining Inhibits Neointimal Growth) registry living in Western Europe and Asia. All patients were treated with at least one endothelial progenitor cell capturing stent. The main study outcome was target vessel failure at the 12-month follow-up, defined as the composite of cardiac death or myocardial infarction and target vessel revascularization. A total of 3504 patients, 2873 living in Western Europe and 731 living in Asia, were assessed in the current analysis. Almost all of the baseline clinical and angiographic characteristics differed significantly between both populations. Target vessel failure at the 12-month follow-up occurred in 11.4% of the Western Europe patients and in 5.6% of the Asian patients (P<0.01). We conclude that differences exist in the baseline, angiographic, and procedural characteristics between Western European and Asian patients undergoing nonurgent PCI. In addition, the 1-year clinical outcomes differ significantly after PCI between Western European and Asian patients. Our results indicate that reports from studies performed worldwide should include both overall and regional subgroup outcomes.
    Coronary artery disease 04/2012; 23(4):271-7. DOI:10.1097/MCA.0b013e328351aaed · 1.30 Impact Factor
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    ABSTRACT: By measuring the pressure decline caused by coronary narrowing, fractional flow reserve (FFR) is an index of the physiological significance of a vessel stenosis. Intracoronary electrocardiogram (IC-ECG) recording from an angioplasty guidewire is more sensitive than standard ECG in detecting regional myocardial ischemia. The aim of the study was to assess if unipolar IC-ECG ST segment recording from angioplasty guidewire during maximal pharmacologic vasodilation could be used as an indirect estimation of FFR results. Forty-eight clinically stable patients with intermediate stenosis underwent FFR evaluation and IC-ECG recording during intravenous adenosine infusion. FFR values were ≤ 0.80 in 26 (54%) patients and > 0.80 in 22 (46%). After adenosine, standard ECG was abnormal in only nine (19%) patients, while IC-ECG showed a significant ST segment shift (IST) in 24 (50%) patients: ST elevation in 19 patients and depression in five). IST was documented in 21/26 patients with FFR ≤ 0.80 (81%) and in 3/22 with FFR > 0.80 (p < 0.001). Sensitivity of IST for predicting an abnormal FFR value was 81%, specificity 86%, positive and negative predictive accuracies were 88% and 79%, respectively. Intracoronary ST segment shift evaluation during adenosine infusion may be of value in assessing the functional significance of a borderline stenosis. The presence of IST during adenosine infusion could obviate the need for additional FFR evaluation.
    Cardiology journal 11/2011; 18(6):662-7. DOI:10.5603/CJ.2011.0030 · 1.22 Impact Factor
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    ABSTRACT: ICD shocks occurring in conscious patients (as in the case of well-tolerated arrhythmias, electromagnetic interference, or oversensing) have a deleterious impact on the quality of life. We evaluated if a hemodynamic parameter, calculated from the right ventricular pressure (RVP) or systemic arterial pressure (AP) signals, could predict early clinical symptoms of cerebral hypoperfusion during induced ventricular tachycardias (VTs). We analyzed 42 tolerated (no symptoms) and 30 untolerated (syncope or severe symptoms within 30 seconds from the onset) VTs, induced during electrophysiological study. The cycle length (CL) and the hemodynamic data (mean AP and RVP, arterial pulse pressure and RV pulse pressure, and maximum AP and RVP dP/dT) were automatically sampled in two VT epochs: the "detection" window, from beat 24 to 32, and the "preintervention" window, immediately before the first therapeutic attempt. Although the CL and all the hemodynamic parameters (expressed as % change versus pre-VT values) were significantly lower in untolerated versus tolerated VTs both at detection and preintervention (with the exception of the mean RVP which progressively increased in both groups), ROC analysis demonstrated that only the preintervention RV pulse pressure showed no overlap between groups, providing 100% sensitivity and positive predictive value. The reduction of the RV pulse pressure is a better predictor of early cerebral symptoms than CL or other hemodynamic indexes during induced VTs. Since long-term RVP monitoring is feasible, this parameter could be incorporated into ICDs decisional path, in the perspective of reducing unnecessary, painful shocks.
    Journal of Cardiovascular Electrophysiology 10/2008; 20(3):299-306. DOI:10.1111/j.1540-8167.2008.01306.x · 2.88 Impact Factor
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    ABSTRACT: The Sequential RR Distribution (SRRD) is introduced as a diagnostic tool for AF detection and classification. SRRD is obtained by computing consecutive RR histogram distributions in successive temporal windows and plotting them prospectically The validation of SRRD for AF detection was performed using the MIT AF database. A interactive graphic interface was developed to navigate in the SRRD and to manually annotate the onset and offset of the AF episodes. Two expert cardiologists were trained to evaluate the SRRD using an home-made database. They were asked to annotate AF events in the MIT database using RR distributions (without accessing the ECG). The results were: episodes sensitivity 97%, episode P+ 78%, duration sensitivity 98%, duration P+ 95%. These results show that sequential RR histogram distributions are accurate enough to allow the detection of AF events without the need of viewing the ECG signal.
    Computers in Cardiology, 2006; 10/2006
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    ABSTRACT: Elevation of cardiac biomarkers after coronary angioplasty (percutaneous coronary intervention [PCI]) reflects periprocedural myocardial damage and is associated with adverse cardiac events. We assessed whether periprocedural myocardial damage that occurs despite successful PCI could be rapidly and easily identified by intracoronary ST-segment recording with the use of a catheter guidewire. In 108 consecutive stable patients undergoing elective single-vessel PCI, we recorded unipolar ECG from the intracoronary guidewire in the distal coronary before PCI and 2 minutes after the last balloon inflation. After PCI, intracoronary ST-segment shift > or = 1 mm from baseline was considered significant. Troponin I levels were measured at baseline and at 8 and 24 hours after intervention, and myocardial damage was defined as troponin I increase above the upper normal value after intervention. All patients had normal cardiac marker values before PCI, and PCI was successful in all (residual stenosis < 20%, Thrombolysis in Myocardial Infarction grade 3 flow). After PCI, long-term follow-up data were collected; myocardial damage was detected in 50 patients (46%), although abnormal creatine kinase-MB values were documented in only 11 (10%). Significant intracoronary ST-segment shift after PCI was present in 40 patients (37%; group A) and absent in the remaining 68 (63%; group B). Procedural myocardial damage was documented in 37 group A patients (93%) and in 13 group B patients (19%; P<0.001); significant ECG changes were found on standard ECG after intervention in only 5 patients (13%) and 1 patient (1%) (P<0.05). Sensitivity of intracoronary ST-segment shift for predicting myocardial damage was 74%, and specificity was 95%, with positive and negative predictive values of 93% and 81%, respectively. On multivariate analysis, intracoronary ST-segment shift was the sole independent predictor of myocardial damage (odds ratio, 54.1; 95% confidence interval, 12.1 to 240; P<0.0001). At a median follow-up of 12+/-5 months, major coronary event-free survival was significantly worse in group A patients (log-rank test chi2=4.0; P<0.05). After successful single-vessel PCI, intracoronary ST-segment shift allows the prompt and inexpensive identification of patients developing myocardial injury, who may require adjunctive therapy and longer in-hospital stay.
    Circulation 10/2006; 114(18):1948-54. DOI:10.1161/CIRCULATIONAHA.106.620476 · 14.95 Impact Factor
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    ABSTRACT: In this paper, we describe two algorithms suitable for the detection of Atrial Fibrillation episodes in very long terms (weeks) ECG monitoring, were the need of onboard implementation requires the development of reliable but simple and easy-to-implement methods. The proposed algorithms are based on the extraction of simple geometric features from the histogram of RR prematurity and delta RR. On the MIT Atrial fibrillation database, the RR prematurity algorithm provides the following performances: episodes sensitivity (S) 91%, episode positive Predictivity (P+) 92%, duration S 93%, duration P+ 97%. For the delta-RR algorithm the results were: episodes S 92%, episode P+ 78%, duration S 89%, duration P+ 90%
    Computers in Cardiology, 2005; 10/2005
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    ABSTRACT: In patients with acute myocardial infarction (AMI), early ST segment elevation resolution on ECG predicts myocardial reperfusion and LV recovery. Intracoronary ECG is more sensitive than surface ECG to detect regional ischemia. In patients undergoing primary percutaneous coronary intervention (PCI), we investigated if failed myocardial reperfusion, despite successful infarct vessel recanalization, could be rapidly and easily identified by intracoronary ST segment monitoring from guidewire recording. We recorded intracoronary and standard ECG during primary coronary stenting (PCI) in 50 patients with AMI (59 +/- 11 years; anterior AMI in 66%). All patients had a successful PCI and underwent 2D echocardiography soon after PCI and 6 months later. Following PCI, intracoronary ST resolution >/= 50% from baseline was documented in 39 patients (78%; group A; from 11 +/- 8 to 1 +/- 2 mm) but not in 11 (22%; group B; from 11 +/- 8 to 8 +/- 5 mm). Group A had slightly shorter ischemic time (202 +/- 94 vs. 238 +/- 112 min in B; P = 0.2) and smaller peak CK values (2,752 +/- 2,038 vs. 4,802 +/- 3,671 U/L in B; P = 0.02). After PCI, ST resolution was found on standard ECG in 34 (87%) group A and in 3 (27%) group B patients. At 6-month follow-up, left ventricular ejection fraction was greater in group A (47% +/- 8% vs. 39% +/- 8% in B; P < 0.001) with improved wall motion score index (from 2.2 +/- 0.3 to 1.7 +/- 0.3 in A; from 2.3 +/- 0.4 to 2.1 +/- 0.4 in B; P < 0.001). There were no significant differences between intracoronary and standard ECG for sensitivity (92% vs. 86%) and specificity (62% vs. 57%) to predict improved infarct zone recovery after 6 months. ST elevation resolution on intracoronary recording during PCI predicts infarct zone recovery. Monitoring ST segment evolution by intracoronary ECG allows prompt and inexpensive identification in the catheterization laboratory of those patients without myocardial reperfusion, who may require adjunctive therapeutic interventions after successful infarct vessel recanalization.
    Catheterization and Cardiovascular Interventions 01/2005; 64(1):53-60. DOI:10.1002/ccd.20236 · 2.40 Impact Factor
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    ABSTRACT: Rescue PTCA is still a debatable procedure and the results published in the literature may not justify routine application of this strategy. To evaluate the hospital outcome of patients undergoing rescue PTCA with the aim of achieving a complete recanalization of the infarct-related artery (IRA)--residual stenosis assessed with QCA < 30% and TIMI 3 forward flow--obtained with adjuvant coronary stenting when needed. From April 1993 to December 1997, 59 consecutive patients underwent rescue PTCA after thrombolysis failure (SK or front-loaded r-tPA, UK) within 6 hours of chest pain onset. All patients had a pre-procedure TIMI 0-1 flow. IRA was the right coronary artery in 23 cases (39%), the left anterior descending in 26 (44%), the left circumflex in 9 (15.3%) and a saphenous vein graft in 1 case (1.7%). In 2 (3.3%) patients, PTCA was not performed (impossibility of crossing the stenosis with the guide-wire). Fifteen patients (26.3%) had a successful procedure (TIMI 3 flow, residual stenosis < 30%) with lone PTCA. Forty-two patients (73.6%) had an intracoronary stent placed (Palmaz-Schatz, Micro-Stent, Multilink, IRIS III): 24 patients (57.1%) for suboptimal angiographic result (TIMI 2 flow, residual stenosis > 30%), 11 patients (26.2%) for dissection, 7 patients (16.7%) for intracoronary thrombosis. All 57 patients had a TIMI 3 flow and a residual stenosis < 30% at the end of the procedure. Mean vessel diameter was 3.22 +/- 0.4 mm, mean balloon size 3.3 +/- 0.4 mm, mean inflation pressure 12 +/- 4 atm, mean residual stenosis 8 +/- 9%. The overall procedure success rate was 96.6%. During hospitalization, three patients (5.1%) suffered subacute reocclusion managed conservatively in one case, with CAGB in another and with re-PTCA in the last one. Three patients (5.1%) had minor vascular complications (groin hematoma) not requiring surgical correction or blood transfusion. No patients died, suffered reinfarction or stroke. All patients were discharged alive and free of angina or clinical heart failure. Coronary stenting performed in the setting of rescue PTCA leads to a good procedural success rate allowing TIMI 3 flow and low residual stenosis (< 30%). Therefore, when conventional balloon angioplasty is unable to achieve an optimal angiographic result, stenting can be accomplished safely, thereby improving the procedural success rate and allowing a bright event-free survival rate.
    Giornale italiano di cardiologia 06/1999; 29(6):630-6.
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    ABSTRACT: Time-variant spectral parameters are used to monitor the Autonomic Nervous System (ANS) status in normal and coronary artery disease (CAD) patients during pharmacological infusion of Dobutamine in Dobutamine Echocardiography Test (DET). During the test, the spectral parameters (LF and HF power, LF/HF ratio) are estimated on a beat-to-beat basis through the time-variant identification of an AutoRegressive (AR) model, using a Recursive Least Square (RLS) algorithm. Different LF responses have been found in the early stages of drug infusion (10-20 γ) sequentially before the appearance of echo, ECG or clinical signs of ischemia. An early increase of LF/LF<sub>basal</sub> value was found in 6 of 8 (75%) positive tests, and only in 2 of 9 (22%) negative ones, suggesting that the different neurovegetative response in the sub-maximal stages of drug infusion may be a marker of an actual or successive ischemia
    Computers in Cardiology 1998; 10/1998
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    ABSTRACT: We sought to evaluate changes in RR interval variability during dipyridamole infusion and dipyridamole-induced myocardial ischemia. Myocardial ischemia and the autonomic nervous system can be mutually interdependent. Spectral analysis of RR interval variability is a useful tool in assessing autonomic tone. We used a time variant autoregressive spectral estimation algorithm that could extract spectral variables even in the presence of nonstationary signals. Two groups were considered: group A (patients with ischemia, n = 15) with effort or mixed angina, angiographically assessed coronary artery disease and positive exercise and dipyridamole echocardiographic test results, and group B (control subjects, n = 10) with normal exercise and dipyridamole echocardiographic test results. We investigated the following variables: RR interval mean and variance, low frequency (LF) and high frequency (HF) power in normalized units, LF ratio (LF/LFbasal power), HF ratio (HF/HFbasal power) and LF/HF ratio. For each test epoch, we calculated for group A and group B the mean value +/- SE of all indexes considered. Differences due to an effect either of group (ischemic vs. control) or of time (including both drug and ischemia effects) were analyzed by using analysis of variance for repeated measurements. Dipyridamole injection was characterized by a reduction of all spectral components in negative test. The LF ratio was the only variable able to discriminate patients with ischemia from control subjects (p < 0.05), whereas a time effect was evident for both mean RR interval and high frequency power in normalized units (p < 0.05). The LF ratio decreased in group B from 1 +/- 0.00 (basal) to 0.31 +/- 0.22 (peak), and increased in group A from 1 +/- 0.00 to 15.41 +/- 6.59, respectively. Results of an unpaired t test comparing the peak values of the two groups were also statistically significant (p < 0.01). Our data show that time variant analysis of heart rate variability evidences an increase in the low frequency ratio that allows differentiation of positive from negative test results, suggesting that the electrocardiogram may contain ischemia information unrelated to ST-T variations, even if their enhancement requires a more complex data processing procedure.
    Journal of the American College of Cardiology 10/1996; 28(4):924-34. DOI:10.1016/S0735-1097(96)00270-7 · 15.34 Impact Factor
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    ABSTRACT: The aim of this study was to assess safety and efficacy of coronary stenting as a strategy for improving PTCA suboptimal angiographic result. From March 1993 to December 1995, 104 patients underwent PTCA during acute myocardial infarction. Unplanned coronary stenting was required in 66 pts (63.5%). Procedural success was obtained in 64 pts (97%). Two patients had an unsuccessful stenting procedure: one patient for a suboptimal stent deployment and another for LAD reocclusion requiring emergency CABG (1.5%). Palmaz-Schatz stents were used in 60 pts (91%) and AVE micro-stent in 6 pts (9%). During the hospital course, subacute reocclusion of the vessel occurred in 3 pts (4.6%); one patient underwent a successful rePTCA while the other two underwent CABG. Two patients had vascular groin complications requiring surgical repair of the femoral artery. During hospitalization, one patient underwent elective CABG for early residual myocardial ischemia. At seventy-two hours from PTCA, one patient (1.5%) died as a result of intestinal infarct. Six months survival rate was 98.3% for 59 pts discharged alive from our department. Ten pts were symptomatic during the follow-up: One patient underwent PTCA on another vessel and the other underwent CABG for a multivessel disease. CABG was used in one patient who presented residual silent ischemia in multivessel coronary artery disease. At six months, the first group of patients (18 pts) underwent planned coronary angiography: Vessel patency was present in 17 patients. One patient had an asymptomatic reocclusion of the treated vessel. This study shows a good angiographic result obtained with intracoronary stenting during primary or rescue PTCA of the infarct-related artery. It does not appear to increase major in-hospital adverse events and may reduce the need for surgical revascularization, reducing in-hospital mortality rate and favorably affecting LVEF.
    The Journal of invasive cardiology 06/1996; 8(4):177-183. · 0.82 Impact Factor
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    ABSTRACT: Computer processing of the exercise electrocardiogram (ECG) has many advantages, but the reliability of the analysis algorithms is not easily evaluable. No standard annotated database, nor recommended practice for testing and reporting performance results is available: thus, performance evaluation of such devices can be accomplished only by using a set of unannotated recordings, obtained in clinical practice. We evaluated the accuracy of an original microcomputer-based exercise test analyzer comparing the ST computer output with the measurements obtained by two experienced cardiologists. Six hundred ECG strips were randomly selected from the exercise test recordings of 60 patients. The ST shift (at J + 80 ms) was blindly assessed by two observers (with the aid of a calibrated lens) and compared with computer measurements. Correlation coefficients, linear regression equations, percent of discrepant measurements, and 95% confidence limits of the mean error were calculated for all leads, peripheral leads, precordial leads, and "stress-test" leads (II, III, aVF, V4, V5, V6). The computer did not analyze five samples on a total of 600 (0.83%) ECG strips because of excessive noise or signal loss, while 51 (8.5%) were considered unreadable by both observers and 67 (11.2%) were rejected by at least one observer. Correlation between the measurements taken by computer and observer(s) measurements was statistically significant (p < 0.001 for all lead groups), no systematic measurement bias was found, and the mean difference was lower than human eye resolution. Our algorithms provide results as good as those provided by trained cardiologists in measuring ST changes occurring during exercise test. However, this study did not evaluate whether computer improvement of the signal-to-noise ratio would allow accurate measurements even on cardiologists' uninterpretable ECG. This potential advantage of computer-assisted analysis could be assessed only by using a dedicated exercise test database, in which different patterns of noise are superimposed on noise-free recordings previously annotated for ST level.
    Clinical Cardiology 03/1996; 19(3):248-52. DOI:10.1002/clc.4960190321 · 2.23 Impact Factor
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    ABSTRACT: The effects of dipyridamole and dipyridamole induced ischemia on the traditional spectral parameters of heart rate variability (HRV) were investigated in normal and coronary artery disease (CAD) patients, who underwent a dipyridamole echocardiography test (DET). The relevant spectral parameters (LF and NF powers, LF/HF ratio) were monitored on a beat-to-beat basis and their variations were linked to the different test epochs and the different pathological events as detected by echocardiographic and electrocardiographic changes. A recursive least square (RLS) identification algorithm was used to this purpose, which is able to track the dynamical changes in nonstationary signals. Spectral parameters were obtained by means of a pole-tracking algorithm which fulfils an efficient extraction of these parameters on a beat-to-beat basis. The estimated parameters allow one, to achieve more information on the autonomic nervous system (ANS) status during drug infusion and the correspondence with the induced ischemia
    Computers in Cardiology 1994; 10/1994