The pressure-derived microvascular resistance reserve and its correlation to Doppler MRR measurement-a proof of concept study.

Background: Microvascular resistance reserve (MRR) is a recently introduced specific index of coronary microcirculation. MRR calculation can utilize parameters deriving from coronary flow reserve (CFR) assessment, provided that intracoronary pressure data are also available. The previously proposed pressure-bounded CFR (CFRpb) defines the possible CFR interval on the basis of resting and hyperemic pressure gradients in the epicardial vessel, however, its correlation to the Doppler wire measurement was reported to be rather poor without the correction for hydrostatic pressure. Purpose: We aimed to determine the pressure-bounded coronary MRR interval with hydrostatic pressure correction according to the previously established equations of CFRpb adapted for the MRR concept. Furthermore, we also aimed to design a prediction model using the actual MRR value within the pressure-bounded interval and validate the results against the gold-standard Doppler wire technique. Methods: Hydrostatic pressure between the tip of the catheter and the sensor of the pressure wire was calculated by height difference measurement from a lateral angiographic view. In the derivation cohort the pressure-bounded MRR interval (between MRRpbmin and MRRpbmax) was determined solely from hydrostatic pressure-corrected intracoronary pressure data. The actual MRR was calculated by simple hemodynamic equations incorporating the anatomical data of the three-dimensionally reconstructed coronary artery (MRRp-3D). These results were analyzed by regression analyses to find relations between the MRRpb bounds and the actual MRRp-3D. Results: In the derivation cohort of 23 measurements, linear regression analysis showed a tight relation between MRRpbmax and MRRp-3D (r 2 = 0.74, p < 0.0001). Using this relation (MRRp-3D = 1.04 + 0.51 × MRRpbmax), the linear prediction of the MRR was tested in the validation cohort of 19 measurements against the gold standard Doppler wire technique. A significant correlation was found between the linearly predicted and the measured values (r = 0.54, p = 0.01). If the area stenosis (AS%) was included to a quadratic prediction model, the correlation was improved (r = 0.63, p = 0.004). Conclusions: The MRR can be predicted reliably to assess microvascular function by our simple model. After the correction for hydrostatic pressure error, the pressure data during routine FFR measurement provides a simultaneous physiological assessment of the macro- and microvasculature.

Technically Challenging Percutaneous Interventions of Chronic Total Occlusions Are Associated with Enhanced Platelet Activation.

Percutaneous coronary intervention (PCI) is a frequently performed treatment option for recanalization in patients with chronic total occlusion (CTO). As CTO-PCIs are often complicated and challenging for interventionalists, the stressful and damaging nature of the procedure can be remarkable, thus platelets can be easily activated. Our aim was to investigate the effect of CTO-PCI on platelet activation and the expression of selected circulating microRNAs (miR) of platelet and endothelium origin after CTO-PCI. In this study, 50 subjects after CTO-PCI were enrolled. Blood samples were obtained before PCI, at 2 days and 3-6 months after the procedure to measure the degree of platelet activation and the level of plasma miR-223, miR-181b, and miR-126. Patients were divided based on the characteristics of the intervention. Patients with higher Japanese CTO scores and longer duration of PCI showed significantly elevated platelet P-selectin positivity (p = 0.004 and p = 0.013, respectively) 2 days after the procedure compared to pre-PCI and increased concentration of soluble P-selectin 3-6 months after the intervention (higher Japanese CTO score: p = 0.028 and longer duration of PCI: p = 0.023) compared to baseline values. Shorter total stent length caused a significantly lower miR-181b expression at 3-6 months after the intervention (p = 0.031), while no difference was observed in miR-223 and miR-126. One stent thrombosis occurred during the follow-up period. Although these technically challenging CTO-PCIs may cause enhanced platelet activation right after the intervention and long-term endothelial cell dysfunction, these interventions are not associated with more adverse clinical events.

Comparison of Safety of RADial comPRESSion Devices: A Multi-Center Trial of Patent Hemostasis following Percutaneous Coronary Intervention from Conventional Radial Access (RAD-PRESS Trial).

Although radial access is the current gold standard for the implementation of percutaneous coronary interventions (PCI), post-procedural radial compression devices are seldom compared with each other in terms of safety or efficacy. Our group aimed to compare a cost effective and potentially green method to dedicated radial compression devices, with respect to access site complications combined in a device oriented complex endpoint (DOCE), freedom from which served as our primary endpoint. Patients undergoing PCI were randomized to receive either the cost effective or a dedicated device, either of which were removed using patent hemostasis. Twenty-four hours after the procedure, radial artery ultrasonography was performed to evaluate the access site. The primary endpoint was assessed using a non-inferiority framework with a non-inferiority margin of five percentage points, which was considered as the least clinically meaningful difference. The cost-effective technique and the dedicated devices were associated with a comparably low rate of complications (freedom from DOCE: 83.3% vs. 70.8%, absolute risk difference: 12.5%, one-sided 95% confidence interval (CI): 1.11%). Composition of the DOCE (i.e., no complication, hematoma, pseudoaneurysm, and radial artery occlusion) and compression time were also assessed in superiority tests as secondary endpoints. Both the cost-effective technique and the dedicated devices were associated with comparably low rates of complications: p = 0.1289. All radial compression devices performed similarly when considering the time to complete removal of the respective device (120.0 (inter-quartile range: 100.0-142.5) for the vial vs. 120.0 (inter-quartile range: 110.0-180) for the dedicated device arm, with a median difference of [95% CI]: 7.0 [-23.11 to 2.00] min, p = 0.2816). In conclusion, our cost-effective method was found to be non-inferior to the dedicated devices with respect to safety, therefore it is a safe alternative to dedicated radial compression devices, as well as seeming to be similarly effective.

Effect of invasive therapeutic coronary interventions on endothelial cell activation and thrombin generation in patients with chronic total coronary occlusion.

BACKGROUND: Percutaneous coronary intervention (PCI) is commonly used treatment for chronic total occlusion (CTO). PCI can be performed in two different ways using wire escalation (WE) or subintimal dissection and reentry (DR) technique. During both procedures patients are treated with anticoagulants, however a substantial activation of coagulation cascade is expected, which may affect clinical outcome. OBJECTIVES: Our aim was to compare the impact of WE and DR techniques regarding endothelial cell activation and thrombin formation. METHODS: Fifty patients after CTO-PCI were enrolled into this study. Blood samples were obtained before PCI, at 48 h and 3-6 months after the intervention to measure soluble endothelium-specific markers and to investigate thrombin generation. RESULTS: Twenty-nine patients were treated with WE, 21 received DR. In the DR group, soluble VCAM-1 (vascular cell adhesion molecule-1) and ICAM-1 (intercellular cell adhesion molecule-1) concentrations were gradually elevated and remained significantly increased at 3-6 months (p = 0.006 and p = 0.037, respectively) compared to pre-PCI. Furthermore, significant decrease in lagtime (p = 0.004) and time to peak (p = 0.002) with a substantial increment in peak thrombin (p = 0.001) were observed in these patients. In contrast, no significant alteration was found in the WE cohort. Clinical complications (myocardial infarction, stroke, thrombosis, revascularization) did not occur in the first 9 months of follow-up period in either group. CONCLUSION: Although DR intervention induces more thrombin generation with a larger degree of endothelium activation compared to WE, this technique does not cause more clinical complications.

The Design and Feasibility of the: Radial Artery Puncture Hemostasis Evaluation - RAPHE Study, a Prospective, Randomized, Multicenter Clinical Trial.

Introduction and Aim: Radial artery approach angiography is the current gold standard for coronary status diagnostics and eventual percutaneous revascularization (PCI). Currently, application of adequate, patent hemostasis based physical torniquets are used for puncture site control, to avoid bleeding, radial artery occlusion and damage (RAO and RAD). The Radial Artery Puncture Hemostasis Evaluation (RAPHE) is a prospective, randomized, multicenter clinical trial designed to investigate new, simplified techniques of radial artery hemostasis utilizing physical compression free methods. Methods and Results: The RAPHE study has been designed to evaluate the efficacy and safety of two non-compression based radial artery hemostasis methods: a 100% chitosan bioactive hemostatic dressing and a purpose-built radial potassium-ferrate based topical hemostasis disc. These devices will be investigated in a standalone configuration. Control group is a standard pneumatic airbladder-based compression device. A total of 600 patients will be enrolled in a three-way randomization (1:1:1) with two study and one control groups. Safety and efficacy endpoints are RAO, puncture site hematoma formation and RAD respectively, consisting of dissection, (pseudo)aneurism and/or fistula formation, measured post-procedure and at sixty days. Conclusion: The results from this trial will provide valuable information on new, simplified methods of radial artery hemostasis options and possibly simplify post-puncture management of patients. Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [NCT04857385].

Pressure- and 3D-Derived Coronary Flow Reserve with Hydrostatic Pressure Correction: Comparison with Intracoronary Doppler Measurements.

Purpose: To develop a method of coronary flow reserve (CFR) calculation derived from three-dimensional (3D) coronary angiographic parameters and intracoronary pressure data during fractional flow reserve (FFR) measurement. Methods: Altogether 19 coronary arteries of 16 native and 3 stented vessels were reconstructed in 3D. The measured distal intracoronary pressures were corrected to the hydrostatic pressure based on the height differences between the levels of the vessel orifice and the sensor position. Classical fluid dynamic equations were applied to calculate the flow during the resting state and vasodilatation based on morphological data and intracoronary pressure values. 3D-derived coronary flow reserve (CFRp-3D) was defined as the ratio between the calculated hyperemic and the resting flow and was compared to the CFR values simultaneously measured by the Doppler sensor (CFRDoppler). Results: Haemodynamic calculations using the distal coronary pressures corrected for hydrostatic pressures showed a strong correlation between the individual CFRp-3D values and the CFRDoppler measurements (r = 0.89, p < 0.0001). Hydrostatic pressure correction increased the specificity of the method from 46.1% to 92.3% for predicting an abnormal CFRDoppler < 2. Conclusions: CFRp-3D calculation with hydrostatic pressure correction during FFR measurement facilitates a comprehensive hemodynamic assessment, supporting the complex evaluation of macro-and microvascular coronary artery disease.

Anatomical Assessment vs. Pullback REsting full-cycle rAtio (RFR) Measurement for Evaluation of Focal and Diffuse CoronarY Disease: Rationale and Design of the "READY Register".

Background: The morphology and functional severity of coronary stenosis show poor correlation. However, in clinical practice, the visual assessment of the invasive coronary angiography is still the most common means for evaluating coronary disease. The fractional flow reserve (FFR), the coronary flow reserve (CFR), and the resting full-cycle ratio (RFR) are established indices to determine the hemodynamic significance of a coronary stenosis. Design/Methods: The READY register (NCT04857762) is a prospective, multicentre register of patients who underwent invasive intracoronary FFR and RFR measurement. The main aim of the registry is to compare the visual estimate of coronary lesions and the functional severity of the stenosis assessed by FFR, as well as the RFR pullback. Characterizations of the coronary vessel for predominantly focal, diffuse, or mixed type disease according to visual vs. RFR pullback determination will be compared. The secondary endpoint of the study is a composite of major adverse cardiac events, including death, myocardial infarction, and repeat coronary revascularization at 1 year. These endpoints will be compared in patients with non-ischemic FFR in the subgroup of cases where the local pressure drop indicates a focal lesion according to the definition of ΔRFR > 0.05 (for <25 mm segment length) and in the subgroup without significant ΔRFR. In case of an FFR value above 0.80, an extended physiological analysis is planned to diagnose or exclude microvascular disease using the CFR/FFR index. This includes novel flow dynamic modeling for CFR calculation (CFRp-3D). Conclusion: The READY register will define the effect of RFR measurement on visual estimation-based clinical decision-making. It can identify a prognostic value of ΔRFR during RFR pullback, and it would also explore the frequency of microvascular disease in the patient population with FFR > 0.80. Clinical Trial Registration: ClinicalTrials.gov (NCT04857762).

Cardiopulmonary Resuscitation With Mechanical Chest Compression Device During Percutaneous Coronary Intervention. A Case Report.

Sudden cardiac death is a leading cause of death worldwide, whereby myocardial infarction is considered the most frequent underlying condition. Percutaneous coronary intervention (PCI) is an important component of post-resuscitation care, while uninterrupted high-quality chest compressions are key determinants in cardiopulmonary resuscitation (CPR). In our paper, we evaluate a case of a female patient who suffered aborted cardiac arrest due to myocardial infarction. The ambulance crew providing prehospital care for sudden cardiac arrest used a mechanical chest compression device during advanced CPR, which enabled them to deliver ongoing resuscitation during transfer to the PCI laboratory located 20 km away from the scene. Mechanical chest compressions were continued during the primary coronary intervention. The resuscitation, carried out for 2 h and 35 min, and the coronary intervention were successful, as evidenced by the return of spontaneous circulation and by the fact that, after a short rehabilitation, the patient was discharged home with a favorable neurological outcome. Our case can serve as an example for the effective and safe use of a mechanical compression device during primary coronary intervention.

Endothelial cell activation is attenuated by everolimus via transcriptional and post-transcriptional regulatory mechanisms after drug-eluting coronary stenting.

We previously found higher level of endothelial cell (EC) activation in patients who suffered from in-stent restenosis after bare-metal stenting compared to subjects who underwent drug-eluting stenting (DES) showing no complications. Here we investigated the potential transcriptional and post-transcriptional regulatory mechanisms by which everolimus attenuated EC activation after DES. We studied the effect of everolimus on E-selectin (SELE) and VCAM1 mRNA levels when human coronary artery (HCAECs) and human umbilical vein ECs were challenged with recombinant TNF-α (100 ng/mL) for 1-24 hours in the presence or absence of everolimus using 0.5 µM concentration locally maintained by DES. EC activation was evaluated via the levels of IL-1ß and IL-6 mRNAs with miR-155 expression by RT-qPCR as well as the nuclear translocation of nuclear factor kappa beta (NF-κB) detected by fluorescence microscopy. To investigate the transcriptional regulation of E-selectin and VCAM-1, TNF-α-induced enhancer RNA (eRNA) expression at p65-bound enhancers in the neighboring genomic regions of SELE and VCAM1 genes, including SELE_-11Kb and VCAM1_-10Kb, were measured in HCAECs. Mature and precursor levels of E-selectin and VCAM-1 repressor miR-181b were quantified to analyze the post-transcriptional regulation of these genes in HCAECs. Circulating miR-181b was analyzed in plasma samples of stented subjects by stem-loop RT-qPCR. TNF-α highly elevated E-selectin and VCAM-1 expression at transcriptional level in ECs. Levels of mature, pre- and pri-miR-181b were repressed in ECs by TNF-α, while everolimus acted as a negative regulator of EC activation via inhibited translocation of NF-κB p65 subunit into cell nuclei, lowered eRNA expression at SELE and VCAM1 genes-associated enhancers and modulated expression of their post-transcriptional repressor miR-181b. Significant negative correlation was observed between plasma miR-181b and soluble E-selectin and VCAM-1 in patients. In conclusion, everolimus attenuates EC activation via reduced NF-κB p65 translocation causing decreased E-selectin and VCAM-1 expression at transcriptional and post-transcriptional level after DES.

Comparison of Platelet Function Guided Versus Unguided Treatment With P2Y12 Inhibitors in Patients With Acute Myocardial Infarction (from the Hungarian Myocardial Infarction Registry).

Evidence is conflicting regarding the clinical benefits of selecting P2Y12 inhibitors based on platelet function testing (PFT). Between March 1, 2013 and March 1, 2014, we collected clinical characteristics and platelet function data in a nationwide acute myocardial infarction (AMI) registry from 15 interventional cardiology centers in Hungary. The risk of all-cause mortality at 1 year were compared after propensity score (PS) matching between patients receiving PFT-guided and unguided P2Y12-inhibitor therapies. High platelet reactivity on clopidogrel (HPRoC) was uniformly defined with the Multiplate assay. A total of 5,583 patients with AMI and coronary intervention were registered. After exclusion of cases with contraindication to prasugrel, propensity matching resulted in a sample of 2,104 patients with well-adjusted characteristics. Clopidogrel was the dominant P2Y12 inhibitor in both groups (unguided: 96% vs PFT guided: 85%, p <0.001). In the PFT-guided group, 19% of patients had HPRoC and 77% of them were switched to prasugrel. According to the adjusted analysis, all-cause mortality at 1 year was significantly lower in the PFT-guided compared with the unguided group (hazard ratio 0.57 [95% confidence interval 0.43 to 0.77], p <0.001). Although prasugrel treatment was not associated with lower all-cause mortality in the overall cohort, patients with HPRoC who switched to prasugrel had significantly lower mortality when compared with those continuing clopidogrel (hazard ratio 0.33 [95% confidence interval 0.12 to 0.92], p <0.05). In conclusion, in patients with AMI, PFT-guided treatment with a high rate of switchover to prasugrel was associated with a lower risk of mortality. Prasugrel was a predictor of lower mortality in patients with HPRoC but not in the overall cohort of AMI.

Underuse of coronary intervention and its impact on mortality in the elderly with myocardial infarction. A propensity-matched analysis from the Hungarian Myocardial Infarction Registry.

BACKGROUND: Data are limited on the real-life use of coronary intervention (PCI) and on its long-term efficacy and safety in elderly patients with acute myocardial infarction (AMI). METHODS: Data from a nation-wide registry of patients treated due to an AMI event in centers of invasive cardiology were analyzed for the potential interaction of age on the utilization of invasive therapy and outcome. Follow-up data of consecutive patients between March 1, 2013, and March 1, 2014 were analyzed. Differences in the risk of all-cause death at 1year between patients undergoing PCI versus others receiving conservative treatment were determined from vital records and were compared with propensity score matching. RESULTS: A total of 8485 consecutive patients were enrolled at 19 centers. Sixty-three percent of the patients were male; the mean age was 65.1±12.4years. The proportion of STEMI cases was 51%. STEMI cases were treated with primary PCI in 91.0% while patients with NSTEACS underwent PCI in 71.0%. The age of patients was a significant determinant of deferring coronary angiography (Hazard ratio (HR): 0.524 95% confidence interval (CI) 0.47-0.59, p<0.001) and PCI (HR: 0.76 95% CI 0.73-0.80, p<0.001). One-year survival after PCI was significantly better both in the overall and in the propensity matched cohort (HR: 0.44 [95% CI: 0.39-0.49] and HR: 0.59 [95% CI: 0.50-0.69], p<0.001, both). This benefit remained consistent in age-dependent subgroup analyses. CONCLUSION: Coronary intervention is underused among the elderly despite the mortality benefit of interventional therapy in myocardial infarction that is consistent in all age groups.

Integrity(®) bare-metal coronary stent-induced platelet and endothelial cell activation results in a higher risk of restenosis compared to Xience(®) everolimus-eluting stents in stable angina patients.

Drug-eluting stenting (DES) has become a reliable tool for coronary stenting; however, its direct effects on platelet and endothelium function differ from those of bare-metal stenting (BMS). This study involved a periprocedural analysis of various biomarkers of cellular activation after elective DES (Xience(®), Abbott Vascular, Santa Clara, CA, USA) or BMS (Integrity(®), Medtronic, Minneapolis, MI, USA). Forty-nine stable angina patients were recruited: 28 underwent BMS, and 21 received everolimus-eluting stents. Samples were collected (i) prior to stenting, (ii) at 24 hours after procedure, and (iii) after 1 month of dual antiplatelet therapy. Platelet activation was analyzed by surface P-selectin positivity in parallel with plasma levels of soluble P-selectin, CD40L and platelet-derived growth factor (PDGF). Endothelial cell (EC) activation was detected by measuring markers of early (von Willebrand factor) and delayed response (VCAM-1, ICAM-1, E-selectin). Patients were followed for 6 months for the occurrence of restenosis or stent thrombosis. Increased platelet activation was sustained regardless of stent type or antiplatelet medication. Concentrations of most EC markers were more elevated after BMS than after DES. No stent thrombosis was seen, but six BMS subjects displayed restenosis with significantly higher sCD40L (779 [397-899] vs. 381 [229-498] pg/mL; p = 0.032) and sICAM-1 (222 [181-272] vs. 162 [153-223] ng/mL; p = 0.046) levels than in those without complication, while DES patients exhibited significantly decreased PDGF (572 [428-626] vs. 244 [228-311] pg/mL; p = 0.004) after 1 month. Nonresponsiveness to antiplatelet drugs did not influence these changes. In conclusion, the degree of platelet and EC activation suggests that Xience(®) DES may be regarded a safer coronary intervention than Integrity(®) BMS, with a lower risk of in-stent restenosis.

Platelet-derived microparticle levels are significantly elevated in patients treated by elective stenting compared to subjects with diagnostic catheterization alone.

Significant platelet reactivity with endothelial damage may occur during percutaneous coronary intervention such as balloon angioplasty and elective stenting in patients with stenotic or occluded arteries in coronary artery disease. Activated platelets express several surface epitopes to aggregate and form heterotypic interactions with leukocytes and endothelial cells, secrete biomarkers to enhance their prothrombotic properties and also generate increased level of microparticles (PMPs). These events may contribute to subacute stent thrombosis induced by the procedure-mediated trauma. Our aim was to study the level of PMPs and other platelet activation markers at an early time point after stenting with bare metal stent in patients on aspirin antiplatelet pre-treatment, and these results were compared to data obtained from subjects with diagnostic catheterization alone. We found that at 15 minutes after the completion of stenting, the levels of PMPs (557 +/- 83/microl versus 325 +/- 42/microl), the platelet P-selectin expression (2.7 +/- 0.3% versus 1.99 +/- 0.1%) and the ratio of platelet-monocyte heterotypic aggregates (48 +/- 4% versus 38 +/- 3%) were significantly (p < 0.05) elevated in patients compared to unstented subjects, but no difference was found in soluble P-selectin values. We suggest that the observed cellular changes are early and sensitive markers to detect the platelet-activating effect of stent implantation.

Effect of timing of clopidogrel administration on 30-day clinical outcomes: 300-mg loading dose immediately after coronary stenting versus pretreatment 6 to 24 hours before stenting in a large unselected patient cohort.

BACKGROUND: The aim of our prospective multicenter Clopidogrel Registry was to evaluate the efficacy and safety of a 300-mg loading dose of clopidogrel at the time of ad hoc stenting in patients with suspected coronary artery disease who were not pretreated with clopidogrel for any reason, and to compare the 30-day clinical event rates with the outcome of patients pretreated with a loading dose of clopidogrel 6 to 24 hours before stenting. METHODS: Between March 2002 and February 2004, 4160 consecutively included patients received a 300-mg loading dose of clopidogrel immediately after (group 1, n = 2679) or 6 to 24 hours before stenting (group 2, n = 1481). RESULTS: The primary end point (triple composite end point of acute myocardial infarction, all-cause death, and urgent repeat target vessel revascularization) at 30 days occurred in 4.74% versus 2.77% in groups 1 and 2, respectively (P = .002). The secondary end point events, the stent thrombosis, occurred significantly more frequently in group 1, with a trend toward increase in incidence of death, target vessel revascularization, or need for glycoprotein IIb/IIIa antagonists during percutaneous coronary intervention. Pretreatment with clopidogrel was associated with more major bleeding (secondary safety end point) (0.41% vs 1.35% in groups 1 and 2, respectively; P = .001). CONCLUSIONS: The results of our multicenter prospective Clopidogrel Registry demonstrate lower efficacy of a 300-mg loading dose of clopidogrel at the time of stenting compared with pretreatment 6 to 24 hours before percutaneous coronary intervention on the 30-day composite clinical end point in the large unselected patient cohort, which suggests the benefit of clopidogrel pretreatment in all incoming patients with suspected significant coronary artery disease scheduled for coronary angiography.

Effects of ad hoc clopidogrel loading versus pre-treatment on P-selectin expression after coronary stent implantation.

Stents represent a thrombogenic surface where one of the earliest events is the deposition of platelets. Activated platelets express neoepitopes that enable them to form homo- and heterotypic aggregates and activate the coagulation system. In this study, we investigated the effects of ad hoc clopidogrel treatment compared to a clopidogrel pretreated group on platelet P-selectin expression. We found that after stent implantation in the ad hoc treated group, P-selectin expression decreased after 1 h, while the initial decrease in platelet count normalized after 4 h. Aspirin non-responsiveness did not influence the results. These data point to the beneficial effect of clopidogrel treatment in reducing platelet reactivity during stenting.

99mTc-MIBI SPECT assessment of the effects of aneurysm resection on the left ventricular morphology.

OBJECTIVE: 99mTc-MIBI SPECT is a widely used myocardial perfusion investigation technique, but few data are available concerning its use to assess the morphological characteristics of a left ventricular aneurysm (LVA) before and after LVA resection. METHODS AND RESULTS: Pre- and postoperative rest 99mTc-MIBI SPECT images were analysed in order to characterize the features of LVAs and the changes in the 3D scintigraphic parameters after apical LVA resection in 6 patients. In the middle horizontal slice an angle was defined to quantify the apical divergence associated with the LVA. After resection, the changes in the divergence angles (DA) were measured as were the changes in the left ventricular volumes (LVV) by volumetric calculations. The mean DA decreased from an average of 38.50 degrees +/- 11.32 degrees preoperatively to 24 degrees +/- 11.84 degrees postoperatively (p = 0.03). The mean LVV also decreased significantly: from 443 +/- 87 ml to 317 +/- 74 ml (p = 0.003). The resectable LVAs were associated with a very low isotope uptake in the apical segments (< 20% relative activity). A DA < 20 degrees was also characteristic of anatomical LVA in all patients. A regression curve plotting divergence angle and the number of left ventricular segments below 20% relative activity showed a significant correlation between them (r = 0.86, p = 0.003). CONCLUSIONS: The significant decreases of DA and LVV after resection reflect favourable morphological changes in the left ventricle (reverse remodelling). We consider 99mTc-MIBI SPECT a useful method for apical LVA detection, it allows an analysis of the morphological (and indirectly the functional) results of the surgery.