Stent thrombosis four and a half years after implantation of a sirolimus-eluting stent.

We report on a case of very late stent thrombosis, 51 months after implantation of a sirolimus-eluting stent and 15 months after clopidogrel discontinuation. This case underlines the possible need for long-term antiplatelet medication in patients receiving sirolimus-eluting stents.

Staged circumferential and ostial pulmonary vein ablation for the treatment of paroxysmal atrial fibrillation.

BACKGROUND: Comparisons between segmental ostial disconnection of the pulmonary veins (PV) and circumferential ablation have produced conflicting results in patients with paroxysmal atrial fibrillation (AF). The aim of this study was to evaluate a staged ablation procedure, every step of which was assessed by means of AF inducibility. METHODS: Twenty-two patients with paroxysmal AF were subjected to three ablation stages during one session: (1) circumferential ablation around the PV ostia, (2) segmental ostial PV isolation, and (3) ablation of areas within the circumferential lines with fractionated electrograms or voltage >0.2 mV as well as linear ablation at the mitral isthmus and the left atrial roof. Endpoint of the procedure was noninducibility of AF at any stage. RESULTS: Average radiofrequency energy delivery, fluoroscopy, and procedure times were 43 +/- 11 minutes, 40 +/- 11 minutes, and 3.8 +/- 0.5 hours, respectively. At 6-months follow-up, four patients experienced recurrence of AF (18%), whereas two additional patients (9%) had left atrial arrhythmias not registered before the procedure. Ninety-five percent of the patients who did not have inducible AF (regardless of the stage of ablation at which noninducibility was achieved) were free of recurrent AF, as opposed to none of the patients in whom AF was inducible at the end of the procedure (log-rank test, P < 0.001). CONCLUSIONS: A staged ablation procedure combing circumferential and ostial PV ablation with AF noninducibilty as endpoint may result in high success rates without the need of prolonged ablation sessions in certain patients with paroxysmal atrial fibrillation.

Proarrhythmic effects of atrial fibrillation ablation techniques.

BACKGROUND: The incidence of proarrhythmia induced by ablation for atrial fibrillation (AF) is not entirely known. We describe the incidence and management of atrial arrhythmias occurring after various techniques for the ablative therapy of AF. METHODS: Ninety-four patients with paroxysmal AF underwent ostial pulmonary vein (PV) ablation (n=54) or circumferential ablation around the PV ostia (n=40). RESULTS: Atrial tachycardia or flutter was detected during the first 6 months after AF ablation in 10 patients. Atrial arrhythmia was more common among patients who underwent circumferential ablation or circumferential with lines (18.2% and 22.2%, respectively) than in those who were treated with other techniques (p = 0.037). The incidence of atrial tachycardia or flutter among patients who underwent ostial ablation or ostial with lines was 2.4% and 8.3%, respectively. No difference was observed in the risk of atrial arrhythmia between patients who underwent ablation with or without additional lines, either ostial (p = 0.398) or circumferential (p = 0.999). Re-ablation was performed in 7 patients with sustained atrial arrhythmia. At 6 months, no recurrence of atrial tachycardia or flutter was.seen in 6 of these patients, nor in 3 patients with non-sustained atrial tachycardia or flutter. CONCLUSIONS: The incidence of atrial tachycardia or flutter following AF ablation is lower for ostial than for circumferential ablation. The addition of lines along the mitral isthmus and between the superior PVs does not significantly affect the risk of ablation-induced arrhythmia. Non-sustained atrial tachycardia or flutter during or early after AF ablation procedures does not require additional ablation.

Patient and staff radiation dosimetry during cardiac electrophysiology studies and catheter ablation procedures: a comprehensive analysis.

AIMS: To perform a comprehensive analysis of all aspects of patient and in-room personnel radiation dosimetry in interventional electrophysiology. METHODS AND RESULTS: Measurements were performed during 19 diagnostic electrophysiology studies and 24 catheter ablations. Kerma-area product and exposure time values were 48.7 (6.4-230) Gy cm2 and 25.5 (4.4-79.2) min for ablation, and 12.5 (4.5-117.2) Gy cm2 and 4.5 (1.2-31) min for diagnostic studies, respectively. Patient effective doses were 15.2 (2.1-59.6) mSv for ablation and 3.2 (1.3-23.9) mSv for diagnostic procedures. Radiation risk to the patient was estimated to be up to eight cases of fatal cancer in 10,000 procedures. The risk of development of fatal cancer was less than 3x10(-6) per procedure to the primary operator. The risk for the nurse and technician was much lower. The dose per procedure for the primary operator was 7.1 microGy at the eyes, 0.79 microGy at the chest under the lead apron, 13.68 microGy at the chest over the apron, 3.82 microGy at the thyroid, 17.76 microGy at the left hand, and 12.11 microGy at the left knee. CONCLUSION: As far as radiation exposure is concerned, electrophysiology studies followed by radiofrequency ablation are safe procedures for both patient and personnel when performed in catheterization laboratories with modern equipment, experienced operators, and standard safety precautions.

Transcoronary transplantation of autologous mesenchymal stem cells and endothelial progenitors into infarcted human myocardium.

The aim of the study was to investigate whether a combination of mesenchymal stem cells (MSCs) capable of differentiating into cardiac myocytes and endothelial progenitors (EPCs) that mainly promote neoangiogenesis might be able to facilitate tissue repair in myocardial scars. Previous studies have shown that intracoronary transplantation of autologous bone marrow stem cells results in improvement of contractility in infracted areas of human myocardium. Eleven patients with an anteroseptal myocardial infarction (MI) underwent transcoronary transplantation of bone marrow-derived MSCs and EPCs to the infarcted area through the left anterior descending artery. Eleven age- and sex-matched patients served as controls. Wall motion score index was significantly lower at follow-up in the transplantation (P = 0.04) but not in the control group. On stress echocardiography, there was improvement of myocardial contractility in one or more previously nonviable myocardial segments in 5 out of 11 patients (all with recent infarctions) and in none of the controls (P = 0.01). Restoration of uptake of Tc(99m) sestamibi in one or more previously nonviable myocardial scars was seen in 6 out of 11 patients subjected to transplantation and in none of the controls (P = 0.02). Cell transplantation was an independent predictor of improvement of nonviable tissue. Intracoronary transplantation of MSCs and EPCs is feasible, safe, and may contribute to regional regeneration of myocardial tissue early or late following MI.

Patient dosimetry during coronary interventions: a comprehensive analysis.

BACKGROUND: We performed a detailed analysis of patient radiation during coronary interventions, comparing dose measurements to established dose reference levels, assessing coronary artery doses, and estimating total radiation risk of fatal cancer. METHODS: We prospectively examined 281 patients who were subjected to 307 percutaneous coronary interventions. RESULTS: The mean kerma area product (KAP) per procedure was 82.1 +/- 47.9 Gy x cm2. Corresponding values for fluoroscopy and digital cineangiography were 28.3 +/- 25.5 Gy x cm2 and 53.8 +/- 35.5 Gy x cm2, respectively, and exposure times were 13.1 +/- 6.8 minutes (87%) and 2.0 +/- 1.5 minutes (13%), respectively. The right anterior oblique caudal and left anterior oblique cranial projections accounted for the highest amount of KAP (24.0% and 23.1%, respectively) compared with other projections. The maximum recorded skin-dose was 182 mGy. Performing a representative procedure on a phantom, the effective dose was 14.9 mSv. The mean coronary dose was 61.7 +/- 38.2 mGy, with a highest calculated dose of 220.1 mGy. The third quartile of KAP measurements was 105 Gy x cm2, the 95th percentile was 175 Gy x cm2, and the mean value of KAP measurements was 82 Gy x cm2. The total risk for the development of fatal cancer was calculated as 83 cases for every 100,000 patients subjected to coronary intervention. CONCLUSIONS: A detailed analysis of patient radiation during coronary interventions is presented. Coronary doses and total radiation risk of fatal cancer are also calculated, and a method for establishing dose reference level values is proposed.

Medical personnel and patient dosimetry during coronary angiography and intervention.

Percutaneous coronary interventions are associated with increased radiation exposure compared to most radiological examinations. This prospective study aimed at (1) measuring entrance doses for all in-room personnel, (2) performing an assessment of patient effective dose and intracoronary doses, (3) investigating the contribution of each projection to kerma-area product (KAP) and irradiation time, (4) comparing results with established DRL values in this clinical setting and (5) estimating the risk for fatal cancer to patients and operators. Measurements were performed during 40 consecutive procedures of coronary angiography (CA), half of which were followed by ad hoc coronary angioplasty (PTCA). KAP measurements were used for patients and thermoluminescent dosimetry for the in-room personnel. The mean KAP value per procedure for CA was 29 +/- 9 Gy cm2. Thirty four per cent of KAP was due to fluoroscopy, whereas the remainder (66%) was due to digital cine. Accordingly, the mean KAP value per PTCA procedure was 75 +/- 30 Gy cm2, and contribution of fluoroscopy is 57%. Effective dose per year was estimated to be 0.04-0.05 mSv y(-1) for the primary operator, and 0.03-0.04 mSv y(-1) for those assisting. Corresponding measurements for radiographer and nurse were below detectable level, implying minimal radiation hazards for them. Regarding radiation exposure, coronary intervention is considered a quite safe procedure for both patients and personnel in laboratories with modern equipment and experienced operators as long as standard safety precautions are considered. Exposure optimization though should be constantly sought through continuous review of procedures.

Plasma profiles of peripheral monocyte-related inflammatory markers in patients with arterial hypertension. Correlations with plasma endothelin-1.

BACKGROUND: This study investigates the plasma activity of inflammatory mediators such as granulocyte-macrophage colony-stimulating factor (GM-CSF), C-C chemokines and soluble adhesion molecules, produced by monocyte-endothelial cell adhesive interaction, in patients with arterial hypertension. METHODS: We studied 66 untreated patients with mild to moderate arterial hypertension (hypercholesterolemic: 34, normocholesterolemic: 32) and 30 sex- and age-matched normocholesterolemic normotensive controls. Plasma concentrations of GM-CSF, macrophage chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1alpha (MIP-1alpha), RANTES (regulated on activation normally T-cell expressed and secreted), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1), as well as plasma endothelin-1 (ET-1), were determined in study population by ELISA and RIA, respectively. RESULTS: Hypertensives exhibited significantly higher levels of GM-CSF (6.5+/-1.3 vs. 2.3+/-0.7 pg/ml, P=0.099), MCP-1 (175+/-31 vs. 120+/-24 pg/ml, P=0.0093), MIP-1alpha (23+/-4 vs. 15+/-2 pg/ml, P=0.0089), RANTES (17+/-4 vs. 14+/-3 ng/ml, P=0.047), sICAM-1 (235+/-39 vs. 187+/-21 ng/ml, P=0.0041), sVCAM-1 (684+/-42 vs. 589+/-23 ng/ml, P=0.0045) and ET-1 (6.1+/-1.5 vs. 2.4+/-0.3 pg/ml, P=0.0095) than those of normotensives. The normocholesterolemic hypertensives had significantly lower levels of GM-CSF, MCP-1, MIP-1alpha, sICAM-1 and sVCAM-1 than hypercholesterolemic hypertensives but higher than normotensives. In hypertensives, ET-1 levels were significantly correlated with mean arterial pressure (r=0.51, P=0.028), MCP-1 values (r=0.45, P=0.047) and sICAM-1 levels (r=0.64, P=0.0090). Significant correlations were also found between LDL cholesterol values and plasma inflammatory factors GM-CSF (r=0.58, P=0.0088), MCP-1 (r=0.49, P=0.040) and sICAM-1 (r=0.53, P=0.034) in the hypercholesterolemic sub-group of hypertensives. CONCLUSIONS: Inflammatory markers of monocyte-endothelial cell adhesive interaction are elevated in hypertensives in comparison to normotensives and may be related to plasma ET-1 activity. The coexistence of hypercholesterolemia may enhance this inflammatory process induced by arterial hypertension.