Micra pacemaker implant after cardiac implantable electronic device extraction: feasibility and long-term outcomes.

AIMS: We aimed at investigating the feasibility and outcome of Micra implant in patients who have previously undergone transvenous lead extraction (TLE), in comparison to naïve patients implanted with the same device. METHODS AND RESULTS: Eighty-three patients (65 males, 78.31%; 77.27 ± 9.96 years) underwent Micra implant at our centre. The entire cohort was divided between 'post-extraction' (Group 1) and naïve patients (Group 2). In 23 of 83 patients (20 males, 86.96%; 73.83 ± 10.29 years), Micra was implanted after TLE. Indication to TLE was an infection in 15 patients (65.21%), leads malfunction in four (17.39%), superior vena cava syndrome in three (13.05%), and severe tricuspid regurgitation in one case (4.35%). The implant procedure was successful in all patients and no device-related events occurred at follow-up (median: 18 months; interquartile range: 1-24). No differences were observed between groups in fluoroscopy time (13.88 ± 10.98 min vs. 13.15 ± 6.64 min, P = 0.45), single device delivery (Group 1 vs. Group 2: 69.56% vs. 55%, P = 0.22), electrical performance at implant and at 12-month follow-up (Group 1 vs. Group 2: pacing threshold 0.48 ± 0.05 V/0.24 ms vs. 0.56 ± 0.25 V/0.24 ms, P = 0.70; impedance 640 ± 148.83 Ohm vs. 583.43 ± 99.7 Ohm, P = 0.27; and R wave amplitude 10.33 ± 2.88 mV vs. 12.62 ± 5.31 mV, P = 0.40). A non-apical site of implant was achievable in the majority of cases (72.3%) without differences among groups (78.26% vs. 70%; P = 0.42). CONCLUSION: Micra implant is an effective and safe procedure in patients still requiring a ventricular pacing after TLE, with similar electrical performance and outcome compared with naïve patients at long-term follow-up.

Left atrial thrombus and smoke resolution in patients with atrial fibrillation under chronic oral anticoagulation.

BACKGROUND: The study aimed to explore the resolution of left atrial and left atrial appendage (LAA) spontaneous echo-contrast or thrombus in patients with nonvalvular atrial fibrillation/flutter (AF/AFL) under chronic oral anticoagulation (OAC). METHODS: A single-center retrospective analysis of patients who underwent a transesophageal echocardiography (TOE) for an electrical cardioversion was conducted. RESULTS: Among 277 TOE performed, 73 cases (26%) of LAA echo-contrast or thrombus were detected, 53 patients with LAA/LA echo-contrast (19%) and 20 (7%) with a thrombus. All patients were under chronic anticoagulation with a VKA (65%) or with a NOAC (35%). The Echo-contrast Group maintained the same OAC strategy in 49 patients (93%). The Thrombus Group kept the same OAC strategy with a NOAC in 6 cases (30%) and changed the strategy in 14 patients (70%), titrating NOAC dose in 1 (5%) and the VKA dose in 4 (20%) and switching from NOAC to VKA in 5 (25%), from VKA to NOAC in 3 (15%), and from NOAC to NOAC in 1 (5%). Smoke resolution was observed in 4/40 cases (10%) of the smoke group and thrombus resolution in 8/15 (53%) of the thrombus group. Patients with thrombus resolution had a lower CHA2DS2-Vasc score (3.5 ± 2 vs 4 ± 1, p = 0.05), were more often under NOAC (37.5 vs 28%, p = 0.07), and had a longer anticoagulation time (7.5 vs 4 months, p = 0.08). CONCLUSION (S): Changing OAC strategy is associated with thrombus resolution in more than 50% of chronically anticoagulated patients.

Comparison between leadless and transvenous single-chamber pacemaker therapy in a referral centre for lead extraction.

PURPOSE: The aim of the study was to compare the long-term clinical and electrical performance of Micra leadless pacemaker with transvenous single-chamber pacemaker (TV-VVI PM) in a high-volume centre for transvenous lead extraction (TLE). METHODS: One-hundred patients (group 1) undergoing Micra implant were matched with 100 patients undergoing TV-VVI PM implant (group 2) by age, sex, left ventricular systolic ejection fraction and previous TLE. RESULTS: The implant procedure was successful in all patients. In group 1, the procedure duration was lower than in group 2 (43.86 ± 22.38 vs 58.38 ± 17.85 min, p < 0.001), while the fluoroscopy time was longer (12.25 ± 6.84 vs 5.32 ± 4.42 min, p < 0.001). There was no difference about the rate of septal implant at the right ventricle (76% vs 86%, p = 0.10). Patients were followed-up for a median of 12 months. No acute and chronic procedure-related complication was observed in group 1, while we reported acute complications in seven patients (7%, p = 0.02) and long-term complications in three patients (3%, p = 0.24), needing for a system revision in 6 cases (6%, p = 0.038), in group 2. One systemic infection occurred in TV-VVI PM group. Electrical measurements were stable during follow-up in both groups, with a longer estimated battery life in group 1 (mean delivered energy at threshold at discharge: 0.14 ± 0.21 vs 0.26 ± 0.22 µJ, p < 0.001). CONCLUSION: Micra pacemaker implant is a safe and effective procedure, with a lower rate of acute complications and system revisions compared with TV-VVI PM, even in a real-life setting including patients who underwent TLE.

Predictors of zero X ray procedures in supraventricular arrhythmias ablation.

To evaluate predictors of zero-X ray procedures for supraventricular arrhythmias (SVT) using minimally fluoroscopic approach (MFA). Patients referred for RF catheter ablation of SVT were admitted for a MFA with an electro-anatomical navigation system or a conventional fluoroscopic approach (ConvA). Exclusion criterion was the need to perform a transseptal puncture. 206 patients (98 men, age 53 ± 19 years) underwent an EP study, 93 (45%) with an MFA and 113 (55%) with a ConvA. Fifty-five had no inducible arrhythmias (EPS). Fifty-four had AV nodal reentrant tachycardia (AVNRT), 49 patients had typical atrial flutter (AFL), 37 had AV reciprocating tachycardia (AVRT/WPW), 11 had focal atrial tachycardia (AT), and underwent a RF ablation. X-ray was not used at all in 51/93 (58%) procedures (zero X ray). MFA was associated with a significant reduction in total fluoroscopy time (5.5 ± 10 vs 13 ± 18 min, P = 0.01) and operator radiation dose (0.8 ± 2.5 vs 3 ± 8.2 mSV, P < 0.05). The greatest absolute dose reduction was observed in AVNRT (0.1 ± 0.3 vs 5.1 ± 10 mSV, P = 0.01, 98% relative dose reduction) and in AFL (1.3 ± 3.6 vs 11 ± 16 mSV, P = 0.003, 88% relative dose reduction) groups. Both AVNRT or AFL resulted the only statistically significant predictors of zero x ray at multivariate analysis (OR 4.5, 95% CI 1.5-13 and OR 5, 95% CI 1.7-15, P < 0.001, respectively). Success and complication rate was comparable between groups (P = NS). Using MFA for SVT ablation, radiological exposure is significantly reduced. Type of arrhythmia is the strongest predictor of zero X ray procedure.

Left ventricular reverse remodeling after transcatheter aortic valve implantation complicated by paroxysmal complete atrioventricular block.

An 86-year-old man with unremarkable clinical history complaining of asthenia and dyspnea was diagnosed with low-flow low-gradient aortic stenosis [LFLG-AS; left ventricular ejection fraction (LVEF) 40% and transaortic mean gradient 37 mmHg, increasing to 52% and 55 mmHg after dobutamine infusion]. The patient underwent transcatheter aortic valve implantation (TAVI; Edwards CENTERA™ 29, Irvine, CA, USA). The procedure and the following hospital stay were free from complications, with no changes on electrocardiography (ECG). Six months later, few syncopal episodes occurred. No signs of orthostatic hypotension or neurologic disorders were present. Echocardiography showed normal functioning of the prosthetic valve and recovery of LV systolic function (LVEF 55%). Baseline ECG and 24-h Holter monitoring were unremarkable. An implantable loop recorder (ILR) was implanted to verify the occurrence of paroxysmal conduction disturbances. One month later, during a syncopal episode, ILR interrogation showed a complete atrioventricular (AV) block. Therefore, a dual chamber, single lead pacemaker was implanted. We are providing the first report of complete AV block occurring months after TAVI, possibly because of reverse LV remodeling following TAVI, with ensuing relative oversizing of the prosthetic valve. This possibility should be considered in patients with syncope not otherwise explained, and previous TAVI, especially in cases of LFLG-AS. .