Late potentials abolition as an additional technique for reduction of arrhythmia recurrence in scar related ventricular tachycardia ablation.

RATIONALE: To evaluate the efficacy of radiofrequency ventricular tachycardia (VT) ablation targeting complete late potential (LP) activity. METHODS AND RESULTS: Sixty-four consecutive patients (pts) with recurrent VTs and coronary artery disease or idiopathic dilated cardiomyopathy were evaluated. Fifty patients (47 male; 66.2 ± 10.1 years) had LPs at electroanatomical mapping; 35 patients had at least 1 VT inducible at basal programmed stimulation. After substrate mapping, radiofrequency ablation was performed with the endpoint of all LPs abolition. LPs could not be abolished in 5 patients despite extensive ablation, in 1 patient because of localization near an apical thrombus, and in 2 patients because of possible phrenic nerve injury. At the end of procedure, prevention of VT inducibility was achieved in 25 of 35 patients (71.4%) with previously inducible VT; VT was still inducible in 5 of 8 patients with incomplete LP abolition; and in 5 of 42 patients (16.1%) with complete LP abolition (P < 0.01). After a follow-up of 13.4 ± 4.0 months, 10 patients (20.0%) had VT recurrences and one of them died after surgical VT ablation; VT recurrence was 9.5% in patients with LPs abolition (4/42 pts) and 75.0% (6/8 pts) in those with incomplete abolition [positive predictive value (PPV): 75%, negative predictive value (NPV): 90.4%, sensibility: 60.0%, and specificity: 95.0%, P < 0.0001); although it was 12.5% (5/40 pts) in patients without inducibility VT after the ablation, and 50% (5/10 pts) in those with inducible VT (PPV: 50%, NPV: 87.5%, sensitivity: 50.0%, and specificity: 87.5%, P = 0.008). CONCLUSIONS: LP abolition is an effective endpoint of VT ablation and its prognostic value compares favorably to that achieved by programmed electrical stimulation.

A case of very late thrombosis of bare metal stent successfully treated with excimer laser coronary angioplasty.

Late thrombosis occurring after bare metal stent (BMS) implantation is a rare complication. However, it is often associated with poor outcome. Mechanisms underlying BMS thrombosis may differ from those underlying drug eluting stent thrombosis. In particular, severe instent restenosis may trigger thrombus formation. This case report describes a very late thrombosis of BMS occurring on an in-stent restenosis. After failure of manual thrombectomy, the case was successfully faced by Excimer Laser Coronary Angioplasty (ELCA). Cases like this may be successfully treated by devices like ELCA combining debulking and thrombus removal capabilities.

Right ventricular substrate mapping using the Ensite Navx system: Accuracy of high-density voltage map obtained by automatic point acquisition during geometry reconstruction.

BACKGROUND: Contact point-to-point electroanatomic mapping (Pt-Map) is a validated tool to evaluate right ventricular (RV) substrate. When using the EnSite NavX system (St. Jude Medical, St Paul, Minnesota), geometry reconstruction by dragging the mapping catheter (Geo-Map) allows for quicker acquisition of a large number of points and better definition of anatomy, but it is not validated for substrate mapping. OBJECTIVE: This study evaluates the feasibility and accuracy of Geo-Map. METHODS: Thirteen patients (mean age 38 +/- 12 years) with RV arrhythmias and an apparently normal heart underwent cardiac magnetic resonance imaging (MRI), Pt-Map, and Geo-Map. The 2 maps were compared in terms of mapping procedural time, radiation time, and total number of points acquired. We finally compared the number and characteristics of low-potential areas on each patient's Pt-Map, Geo-Map, and cardiac MRI. RESULTS: Geo-Map required significantly shorter mapping and radiation times in comparison to Pt-Map (12.4 +/- 4.6 vs. 31.9 +/- 10.1 and 5.8 +/- 2.1 vs. 12.1 +/- 3.9, P <.001). Furthermore, Geo-Map was based on a significantly higher density of points in comparison to Pt-Map (802 +/- 205 vs. 194 +/- 38, P <.001). Taking into consideration the total number of RV regions analyzed, the Pt-Map and Geo-Map disagreed in 2 of 65 (3%) regions (P = NS), which only Geo-Map identified as low-potential areas and indeed corresponded to wall motion abnormalities on MRI. CONCLUSION: Voltage maps obtained through RV geometry acquisition have accuracy comparable to that of conventional point-by-point mapping in detecting low-voltage areas, have a good correlation with MRI wall motion abnormalities, and allow a significant reduction in procedural time and x-ray exposure.

The complex link between oxidised low-density lipoprotein and unstable angina.

OBJECTIVE: The role of oxidised low-density lipoprotein (ox-LDL) in plaque destabilisation is controversial; therefore we aimed at comparing plaque and plasma ox-LDL content in stable and unstable ischaemic syndromes. We also assessed the correlation between plaque or plasma ox-LDL and angiographic complex stenosis morphology. METHODS: Ten consecutive patients with chronic stable angina (SA) and 10 consecutive patients with unstable angina (UA) were studied. Plaque sections obtained by directional coronary atherectomy were immunostained with the monoclonal antibody mAb-4E6, which recognises several oxidation epitopes on LDL (mAb-4E6 ox-LDL), and with the monoclonal antibody mAb-1H11 (mAb-1H11 ox-LDL), which recognises malondialdehyde-modified LDL. An mAb-4E6-based competition ELISA was used for quantification of ox-LDL in plasma. C-reactive protein serum levels were measured by a high-sensitivity nephelometric assay. An angiographic analysis was performed to assess severity and extent of coronary atherosclerotic disease and stenosis morphology. RESULTS: Percent plaque area occupied by mAb-4E6 ox-LDL or mAb-1H11 ox-LDL was similar in patients with SA or UA (22.4 +/- 13.1 vs. 21.1 +/- 19.7%, P = 0.8 and 19.3 +/- 10.4 vs. 16.8 +/- 16.9%, P = 0.6, respectively), whereas ox-LDL plasma levels were significantly higher in patients with UA than in patients with SA (2.4 +/- 1.1 vs. 0.9 +/- 0.6 mg/dl; P = 0.03). Furthermore, a significant correlation was found between plasma levels of ox-LDL and the number of angiographically complex lesions (P = 0.03) or C-reactive protein serum levels (P = 0.04). CONCLUSIONS: Neither plaque mAb-4E6 ox-LDL nor plaque mAb-1H11 ox-LDL seem to be a major trigger of coronary plaque instability. However, circulating ox-LDL might be involved in plaque vulnerability and coronary artery disease activity.

Directional atherectomy before stenting versus stenting alone in percutaneous coronary interventions: a meta-analysis.

Plaque debulking before stenting is still controversial. We performed a meta-analysis of 12 randomized and non-randomized trials comparing directional coronary atherectomy (DCA) before stenting versus stenting alone. Angiographic end points were acute gain, late loss and angiographic restenosis rate. Clinical end points were early major adverse cardiac events [MACEs: death, Q-wave myocardial infarction (MI), non-Q-wave MI], late MACEs (death, Q-wave MI) and target lesion revascularization (TLR). Data are expressed as odds ratio (OR) with 95% confidence intervals (CI) or weighted mean difference (WMD) with 95% CI, as appropriate. A total of 1216 patients undergoing DCA before stent and 1484 patients undergoing stent alone have been included. DCA before stent was associated to a better acute gain compared to stenting alone (WMD 0.23, [0.18-0.28]; p<0.0001), to a striking reduction of angiographic restenosis rate (OR of 0.67, [0.54-0.84], p=0.0003) and to a significantly lower rate of late TLR (OR 0.73 [0.59-0.91], p=0.006). Late loss did not differ between the two groups (WMD 0.00 [-0.08 and 0.08], p=0.98). We found a higher rate of early MACEs for the combined approach (OR 1.87 [1.16-3.02], p=0.01), with similar prevalence of late MACEs (OR 0.83 [0.65-1.06], p=0.13). In conclusion, this meta-analysis demonstrates that DCA before stenting is superior to stenting alone with regard to acute angiographic results and TLR with a similar prevalence of late MACEs. The higher prevalence of early MACEs with DCA before stenting, however, is disturbing and probably related to distal embolization.