Edoardo Verna

Assessment of myocardial area at risk by technetium-99m sestamibi during coronary artery occlusion: comparison between three tomographic methods of quantification

The aim of this study was to directly compare three currently used quantitative methods of analysis of technetium-99m sestamibi images in patients with selective balloon-induced transmural ischaemia. The area at risk (AR) was assessed in 19 patients undergoing singlevessel percutaneous transluminal coronary angioplasty by injecting the99mTc-sestamibi at the time of coronary artery occlusion during balloon inflation. After imaging, the patients were classified according to localization of the perfusion defect as having anteroseptal (group I, 11 patients) or posterolateral defects (group II, eight patients). The planimetric technique based on polar maps, proposed by Verani et al. (J Am Coll Cardiol, 1988) (method A), the method described by Tamaki et al. (Circulation, 1982) (method B) and the technique validated by OConnor et al. (Eur J Nucl Med, 1990) (method C) were tested. Three threshold values of 45%, 50% and 60% of the maximum left ventricular count were used to define the limits of the perfusion defect. The mean values of the AR calculated by the three techniques with the original cut-off level (method A=16.5%±12.9; method B=10.4%±7.6%; method C=29.6%±15.7%) were statistically different (one-way analysis of variance:P<0.001; pairedt test: method A vs B,P=0.003; method B vs C and method A vs C,P<0.0001). There was no significant difference between the mean values of the AR estimated by the three methods using the same cut-off levels. The use of 60% of the maximum left ventricular count provided the best correlation between the techniques (method A vs B,r=0.95; method B vs C,r=0.92; method A vs C,r=0.95). Nevertheless, a difference >10% between the values of AR assessed by the three methods was found in four subjects. There was no significant difference between the three methods in the evaluation of AR in the subjects of group I and group II. Reproducibility was good for all methods. It is concluded that the three methods of analysis of the AR by99mTc-sestamibi SPET imaging showed comparable performance and good reproducibility using the same cut-off level. The location of perfusion defect does not affect the comparability of the three techniques. We suggest the use of a cut-off level of 60% for all three methods in the assessment of the AR by99mTc-sestamibi SPET imaging.

Assessment of cardiac asynchrony by radionuclide phase analysis: Correlation with ventricular function in patients with narrow or prolonged QRS interval

Conflicting data exist on the relation between the synchronism of cardiac contraction and ventricular function.

Performing versus deferring coronary angioplasty based on functional evaluation of vessel stenosis by pressure measurements: a clinical outcome study.

Aim The present study aimed to prospectively evaluate whether application of the concept of fractional flow reserve (FFR) guides the immediate decision to perform or to defer coronary angioplasty in unselected consecutive patients with one or more angiographically intermediate (50–70%) stenoses and non-conclusive or lacking non-invasive testing. Methods We studied 112 patients (81 males and 31 females, aged 31–81 years) including 71 multivessel disease patients (63%) and 30 patients (27%) with unstable symptoms. FFR was measured with the use of a pressure-wire after adenosine-induced hyperaemia and compared with quantitative coronary angiography in 171 stenoses. Coronary angioplasty was performed in the presence of an FFR < 0.75 and deferred if FFR was ≥ 0.75. Cardiac events including death, myocardial infarction, recurrent angina or symptoms requiring repeated hospitalization and target vessel revascularization (TVR) were recorded during a median period of 34 months (interquartile range 9–54 months). Results Coronary angioplasty was deferred based on FFR results in 54 patients (group I). In the remaining 58 patients, angioplasty was performed in one or more stenoses that were significant by FFR and deferred in non-significant stenoses (group II). Overall, coronary angioplasty was performed in 71 vessels (41%) and deferred in 100 (59%). Cumulative cardiac events occurred in 12.9% of group I patients and in 24.1% of group II patients (χ2 = 1.57, P = 0.20). TVR was required in 5% of the stenoses untreated based on FFR result in both groups and in 12.6% of stenoses that underwent coronary angioplasty (χ2 = 3.25, P = 0.07; relative risk = 2.5, 95% confidence interval = 0.88–8.61). Conclusions In patients with angiographically intermediate stenoses, functional evaluation by FFR to select lesions that do not need to be treated invasively is safe. Unnecessary angioplasty and stenting may be saved in more than one half of individual coronary stenoses. The risk of major cardiac events and TVR of functionally non-significant stenoses is lower than the risk associated with coronary angioplasty. Our observations further support the use of pressure wire for physiological assessment of coronary artery stenosis in the catheterization room.

Endothelial dysfunction versus early atherosclerosis: A study with high resolution imaging

Endothelial dysfunction versus early atherosclerosis: A study with high resolution imaging☆☆☆ Olivia Manfrini , Edina Cenko , Edoardo Verna , Jorge A. Salerno Uriarte , Raffaele Bugiardini a,⁎ a University of Bologna, Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale, Bologna, Italy b University of Insubria, Hospital of Circolo and Foundation Macchi, Department of Cardiology, Varese, Italy c University of Insubria, Department of Clinical Medicine, Varese, Italy

Evaluation of baseline contractile reserve vs dyssynchrony as a predictor of functional improvement and long term outcome after resynchronization pacing therapy: A radionuclide stress study

AimTo assess the predictive value of baseline ventricular dyssynchrony and myocardial contractile reserve (mCR) in identifying responders to cardiac resynchronization therapy (CRT).MethodsWe prospectively studied 57 patients selected for CRT according to current recommendations. Regional dyssynchrony was evaluated by parametric phase imaging of ecg-gated equilibrium radionuclide angiography (ERNA). The mean inter-ventricular phase delay and the standard deviation to mean left ventricular (LV) phase angle were used as a measure of inter- and intra-ventricular dyssynchrony, respectively. Change in LV ejection fraction (LVEF) during low-dose dobutamine (LDD) was measured to assess mCR. ERNA was repeated at 6xa0months to evaluate changes in LVEF after CRT. Combined end-points of re-hospitalization for heart failure, heart transplantation, and cardiac death were assessed over a period of 76xa0months (mean 43xa0±xa031).ResultsBaseline dyssynchrony was present in most patients (85%). After CRT only one half of patients showed a reduction in intra-ventricular dyssynchrony and 33% an increase in LVEF by >5%. Improvement of LVEF was not predicted by baseline LVEF, clinical presentation, dyssynchrony parameters or QRS duration. There was a significant relationship between changes in LVEF during LDD testing and after CRT (rxa0=xa00.65; Pxa0<xa0.0001). Logistic regression analysis identified mCR as independent predictor of improvement in LVEF (Pxa0=xa0.039; ORxa0=xa03.84; CI 95%xa0=xa01.06-13.9), resynchronization (Pxa0=xa0.046; ORxa0=xa04.20; CI 95%xa0=xa01.03-17.2), and event-free survival (Pxa0=xa0.002; ORxa0=xa00.10; CI 95%xa0=xa00.02-0.43).ConclusionsIn patients with left ventricular dysfunction and baseline dyssynchrony as assessed by ERNA, evaluation of mCR during LDD may help predicting functional improvement and selecting potential responders to CRT.

Epicardial and microvascular coronary vasomotor dysfunction and its relation to myocardial ischemic burden in patients with non-obstructive coronary artery disease

AimTo assess the relative contribution of epicardial endothelium-dependent (EDD) and microvascular endothelium-independent (EIMVD) coronary vasomotor dysfunction to the extent of myocardial ischemia in patients with normal angiograms or non-obstructive coronary artery disease (NOCAD).MethodsCoronary vasomotion was evaluated by quantitative angiography and blood flow (CBF) measurements during intracoronary acetylcholine, nitroglycerine, and adenosine in 101 patients. Myocardial SPECT ischemic burden was evaluated by semi-quantitative scoring of summed stress (SSS) and summed ischemic (SDS) perfusion defect size.ResultsCoronary vasomotor dysfunction was found in most patients (83; 77%) with a divergent behavior of EDD and EIMVD in one half of them (52.4%). There was no significant difference in SDS between patients with and without EIMVD, whereas SDS was significantly greater in subjects with EDD as compared to patients with normal response to acetylcholine (4.31xa0±xa02.44 vs 1.35xa0±xa01.45; Pxa0<xa0.0001). Patients with EDD, either alone or in combination with EIMVD, had significantly higher SSS as compared to patients with lone EIMVD or normal vasomotor function (8.50xa0±xa05.32; 5.55xa0±xa03.21; 2.60xa0±xa02.14; and 1.74xa0±xa01.66, respectively; Pxa0<xa0.0001). Acetylcholine CBF correlated inversely with both SDS (rxa0=xa0−0.545; Pxa0<xa0.001) and SSS (rxa0=xa00.538; Pxa0<xa0.001).ConclusionsIn NOCAD patients with symptoms and signs of myocardial ischemia, vasomotor dysfunction is common. EDD is associated with greater extent of ischemia as compared to isolated EIMVD. Thus, assessment of both EIMVD and EDD is needed to recognize mechanisms of ischemia and identify patients with greater ischemic burden.

Abnormal coronary vasoreactivity in transient left ventricular apical ballooning (tako-tsubo) syndrome

BACKGROUNDnThe exact etiology and pathophysiologic mechanisms of tako-tsubo syndrome (TTS) remain controversial.nnnOBJECTIVEnTo further evaluate the abnormal coronary vasoreactivity and its possible anatomical substrate in TTS.nnnMETHODSnWe studied 47 patients (46 women; age 67±12years) who underwent diagnostic cardiac catheterization and evaluation of coronary vasoreactivity by sequential acetylcholine (Ach), nitroglycerine and adenosine testing with angiographic and intracoronary pressure-Doppler flow monitoring. Coronary artery wall morphology was also evaluated by intravascular ultrasound (IVUS) imaging in 45 vessels of 43 patients.nnnRESULTSnAbnormal coronary vasoconstriction to Ach stimulation was elicited in 40 patients (85%) involving the LAD artery and its branches in 39 (83%). Abnormal microvascular function was seen in 39 (83%) patients. Overall, hyperemic microvascular resistance index (HMR) was higher and Doppler coronary flow velocity reserve (CFVR) was lower in the LAD artery territory as compared to the reference territories (2.64±1.23 vs 2.05±0.56; p=0.008 and 1.95±0.7 vs 2.3±0.6; p=0.018, respectively). IVUS revealed no plaque rupture, dissection or thrombosis but occult plaque formation and myocardial bridging were found as a possible anatomical substrate of endothelial dysfunction in 67% and 48.8% patients respectively.nnnCONCLUSIONSnA global failure of coronary vasomotor function was demonstrated in most TTS patients. These findings implicate abnormal vasoconstrictive response to the activation of the sympathetic system as a potential mechanism involved in the pathogenesis of myocardial stunning in TTS.nnnPERSPECTIVESnCompetency in medical knowledge: Abnormal coronary vasoconstriction secondary to endothelial dysfunction may actively contribute to the clinical manifestation of acute coronary syndromes in patients with non-obstructive coronary disease. Translational outlook 1: TTS patients reveal a global failure of vasomotor function with both vasoconstrictive response to acetylcholine and increased hyperemic microvascular resistances in the territory of myocardial stunning. They may also show occult coronary atherosclerosis and myocardial bridging as the anatomic substrates of endothelial dysfunction. Translational outlook 2: The cardiac phenotype of TTS includes a high prevalence of coronary vasomotor disturbances. These findings implicate abnormal vasoconstrictive response to the activation of the sympathetic system as a potential mechanism involved in the pathogenesis of TTS in post-menopausal women. Thus, a systematic evaluation of coronary vasoreactivity could better characterize the syndrome.

High Energy Transcatheter Cardioversion for Chronic, Poorly Tolerated Atrial Fibrillation

Between August 1991 and May 1993, 14 patients affected by chronic, poorly tolerated atrial fibrillation (AF) were submitted to high energy transcatheter Cardioversion. Mean duration of AF was 27.4 ± 45.1 months. In nine patients (56%), AF lasted for > 1 year. All patients had underlying heart disease, with a mean LVEF of 45.2%± 11.8% and a NYHA Class ≥ II. Previously, a mean of 2.9 ± 1.3 patients failed external electrical Cardioversion, with and without antiarrhythmics, have been attempted. Transcatheter conversion was performed by pulling the His‐bundle catheter back in the right atrial cavity until no His bundle activity was recorded on distal poles, and then delivering the shock between a proximal electrode (cathode) and a back plate (anode). In all patients, transcatheter conversion restored sinus rhythm. Transient complete atrioventricular (AV) block was observed in four patients (28%), and treated by prophylactic temporary pacing. At 1 year, seven patients (50%) were still in sinus rhythm. In this series, only younger age could be related to AF recurrence (46.1 ± 10.8 vs 63.4 ± 6.8 years, P ≤ 0.004), even if prophylaxis with amiodarone showed a positive trend versus sinus rhythm maintenance (71 % vs 14%, P = NS). In conclusion, high energy transcatheter Cardioversion is a safe and effective method of restoring sinus rhythm in patients with chronic, poorly tolerated AF. In these patients, high energy transcatheter Cardioversion could be considered as an alternative to AV node ablation techniques, avoiding pacemaker implant and embolic risk. Larger studies are needed to determine better patient selection and delineate drug strategy after the procedure.

Clinical role of post-angioplasty hyperemic microvascular resistances in chronic ischemic left ventricular dysfunction.

Aims To investigate the impact of hyperemic microvascular resistances (HMRs) on myocardial perfusion and contractility after percutaneous coronary intervention (PCI) in chronic ischemic left ventricular dysfunction (CILVD). Methods The current retrospective study included 48 patients with CILVD of the left anterior descending territory undergoing HMRs assessment before and after PCI with a dual-sensor intracoronary pressure-flow wire. The severity of resting myocardial underperfusion and contractile dysfunction of the left anterior descending territory was scored as summed rest score (SRS-T) by single photon emission tomography, wall motion score index (WMSI-T) and left ventricular ejection fraction (LVEF) by transthoracic echocardiography before PCI and after 3 months. Patients were divided into two groups according to the mean post-PCI HMRs. Results Mean post-PCI HMRs were 2.05u200a±u200a0.43u200ammHg/cm/s; increased HMRs (i.e. >2u200ammHg/cm/s) were found in 17 patients (35.4%, group B) (3.29u200a±u200a0.77u200ammHg/cm/s), whereas 31 patients (64.6%, group A) showed lower values (1.35u200a±u200a0.34u200ammHg/cm/s; Pu200a<u200a0.001). Pre-PCI HMRs, WMSI-T and SRS-T were similar among groups. After PCI, a significant improvement of LVEF, WMSI-T and SRS-T was observed only in group A (6.6u200a±u200a7.4%, 0.44u200a±u200a0.42 and 3.9u200a±u200a2.9, respectively) compared with group B (1.3u200a±u200a1.9%, 0.02u200a±u200a0.07 and 1.1u200a±u200a1.9; Pu200a=u200a0.011, Pu200a<u200a0.001 and Pu200a=u200a0.028, respectively). Post-PCI HMRs predicted the absence of improvement of LVEF and WMSI-T at a cutoff value of 1.95u200ammHg/cm/s (area under the curve 0.69 and 0.73; Pu200a=u200a0.038 and 0.017, respectively), with a positive predictive value of 96 and 100%, respectively. Conclusion Increased post-PCI HMRs may predict the lack of functional improvement of the revascularized myocardium in CILVD.

Setting the Stage: How to Perform Intracoronary Pressure Measurements

FFR has become an established technology, and alternative approaches, like the instantaneous flow reserve (iFR), are currently being validated. FFR and iFR are generally easy to perform and interpret, but, as with all other technologies, oversimplification also carries risks. In the first chapter of this book, we present the basics of FFR measurements, including basic tips and tricks, and a short introduction to the devices available on the market.