Long-term results of ablation index guided atrial fibrillation ablation: insights after 5+ years of follow-up from the MPH AF Ablation Registry.

Background: Catheter ablation (CA) for symptomatic atrial fibrillation (AF) offers the best outcomes for patients. Despite the benefits of CA, a significant proportion of patients suffer a recurrence; hence, there is scope to potentially improve outcomes through technical innovations such as ablation index (AI) guidance during AF ablation. We present real-world 5-year follow-up data of AI-guided pulmonary vein isolation. Methods: We retrospectively followed 123 consecutive patients who underwent AI-guided CA shortly after its introduction to routine practice. Data were collected from the MPH AF Ablation Registry with the approval of the institutional research board. Results: Our patient cohort was older, with higher BMI, greater CHA2DS2-VASc scores, and larger left atrial sizes compared to similar previously published cohorts, while gender balance and other characteristics were similar. The probability of freedom from atrial arrhythmia with repeat procedures is as follows: year 1: 0.95, year 2: 0.92, year 3: 0.85, year 4: 0.79, and year 5: 0.72. Age >75 years (p = 0.02, HR: 2.7, CI: 1.14-6.7), BMI >35 kg/m2 (p = 0.0009, HR: 4.6, CI: 1.8-11.4), and left atrial width as measured on CT in the upper quartile (p = 0.04, HR: 2.5, CI: 1-5.7) were statistically significant independent predictors of recurrent AF. Conclusion: AI-guided CA is an effective treatment for AF, with 95.8% of patients remaining free from atrial arrhythmia at 1 year and 72.3% at 5 years, allowing for repeat procedures. It is safe with a low major complication rate of 1.25%. Age >75 years, BMI >35 kg/m2, and markedly enlarged atria were associated with higher recurrence rates.

Vitamin D Deficiency Predicts Poor Clinical Outcomes in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy.

BACKGROUND AND AIMS: Resynchronization therapy (CRT) improves mortality and induces reverse remodeling in heart failure (HF) patients with reduced ejection fraction and wide QRS. Nonetheless, some patients do not improve despite the optimal medical therapy and right indications for device implantation. Therefore, finding biomarkers suitable for identification of those patients is crucial. Vitamin D plays a classic hormonal role in the regulation of bone metabolism and also has physiological functions in wide range of nonskeletal tissues. Based on recent studies, low levels of vitamin D seem to directly contribute to pathogenesis and worsening of HF. We planned to assess the role of vitamin D levels on clinical outcomes of HF patients undergoing CRT. METHODS AND RESULTS: We enrolled 136 HF patients undergoing CRT. Total plasma vitamin D levels were measured at baseline and 6 months later. Primary endpoint was 5-year all-cause mortality; secondary endpoint was lack of good clinical response, defined as less than 15% increase of left ventricular ejection fraction after six months. During follow-up, 58 patients reached the primary, and 45 patients reached the secondary endpoint. Vitamin D levels less than 24.13 ng/mL predicted 5-year mortality (p = 0.045) and poor clinical response (p = 0.03) after adjusting to all significant baseline predictors. CONCLUSION: Our study showed that vitamin D deficiency has a significant impact in heart failure patients; it is an independent predictor of lack of midterm clinical response and long-term mortality in patients undergoing CRT. Therefore, monitoring vitamin D status of heart failure patients could be of clinical significance.

Radiofrequency ablation of focal atrial tachycardia: Benefit of electroanatomical mapping over conventional mapping.

BACKGROUND: Catheter ablation is a proven therapy of focal atrial tachycardia. However limited information is available about the additional value of electroanatomical over conventional mapping methods for this specific arrhythmia. METHODS: Consecutive catheter ablation procedures of FAT were analyzed in two cardiology centres. Only conventional mapping was used in 30 of the 60 procedures whereas additionally CARTO mapping was performed in another 30 procedures. Acute, six-month success rate, and procedural data were analyzed. RESULTS: Localization of ectopic foci is congruent with previously published data. There was no statistically significant difference between procedure time and fluoroscopy time using additionally CARTO mapping, compared to conventional mapping only. Acute success rate was higher in procedures guided by CARTO mapping than in procedures based on conventional mapping (27/30 vs. 18/30, p = 0.0081). During the 6-month follow-up period there was a better outcome (p = 0.045) in case of CARTO guided procedures (success: 11 cases, partial success: 12 cases, failure: 4 cases) compared to conventional mapping (success: 4 cases, partial success: 18 cases, failure: 7 cases). CONCLUSIONS: Catheter ablation of focal atrial tachycardias using the CARTO electroanatomical mapping system seems to provide higher acute and 6-month success rate compared to ablation using conventional mapping methods only.

Complement activation and its prognostic role in post-cardiac arrest patients.

Cardiac arrest causes generalized ischaemia/hypoxia, and subsequent resuscitation inflicts reperfusion injury, the pathology of which is not fully understood. Moreover, predicting the prognosis of comatose, post-cardiac arrest patients is a complex clinical challenge. We hypothesized that the extent of complement activation might be a reliable predictor of mortality in this population. Forty-six comatose cardiac arrest patients were enrolled into our prospective cohort study, conducted in a tertiary care university clinic. All subjects were cooled to 32-34 °C body temperature for 24 h and then allowed to rewarm to normothermia. All patients underwent diagnostic coronary angiography. On admission, at 6 and 24 h, blood samples were taken from the arterial catheter. In these, complement products (C3a, C3, C4d, C4, SC5b9 and Bb) were measured by ELISA in blood samples. Patients were followed up for 30 days; 22 patients (47.8%) died by the end of this period. We observed that complement activation (determined as the C3a to C3 ratio) was higher in non-survivors than in survivors at each time point. In the multivariate Cox regression analysis, the C3a/C3 ratio determined 24 h after the initiation of therapeutic hypothermia predicted 30-day mortality regardless of age, sex and the APACHE II score. Complement activation occurs in post-cardiac arrest patients, and its extent correlates with 30-day survival. The C3a/C3 ratio might prove useful for estimating the prognosis of comatose post-cardiac arrest patients.

The level of complement C3 is associated with the severity of atherosclerosis but not with arterial calcification in peripheral artery disease.

AIM: Recent evidences show correlations between atherosclerosis and the serum level of third component of complement (C3). However, there is less data on the connection of C3 and the severity of atherosclerosis. The aim of our study was to evaluate the association of serum C3 levels with atherosclerosis and arterial calcification in patients with chronic lower extremity atherosclerosis. METHODS: In a single centre cross-sectional study 103 patients and 109 healthy controls were examined. Sera were analyzed for C3. To identify the severity of atherosclerosis and calcification, ankle-brachial Doppler index, angiographic Bollinger score, arterial calcification score and carotid intima-media thickness was determined. RESULTS: Serum level of C3 was significantly higher in the lower extremity atherosclerosis group than in healthy patients (P=0.00004). In the patient group, serum level of C3, C4 was significantly and inversely associated with ABI (r=-0.246, P=0.014), (r=-0.259, P=0.011). C3 inversely correlates with Bollinger score (r= -0.357, P=0.028). Among our patients no correlation was found between C3 levels and CS (P=0.672, r=-0.046) or between C3 levels and carotid IMT (r=0.104, P=0.351). The serum levels of different complement components were associated with C-reactive protein, Hba1c, peptide-C and insulin. CONCLUSION: Our results suggest that C3 serum levels are associated with ABI and angiographic parameters of atherosclerosis, but do not relate to the severity of calcification.

Left ventricular untwisting in athlete's heart: key role in early diastolic filling?

Untwisting contributes to left ventricular filling through suction generation. We sought to investigate diastolic function and untwisting dynamics in different forms of left ventricular hypertrophy: in athlete's heart and hypertrophic cardiomyopathy. Elite athletes in kayaking, canoeing and rowing (n=28), patients with hypertrophic cardiomyopathy (HCM, n=15) and healthy sedentary volunteers (n=13) were compared. Left ventricular volumes, wall thickness-to-volume ratio were assessed by cardiac MRI. Following conventional and tissue Doppler measurements, untwist and untwist rate were determined by speckle tracking echocardiography. Wall thickness-to-volume ratio describing remodelling was significantly higher in HCM, but similar in athletes and controls (athlete vs. HCM vs. control: 0.107±0.019 vs. 0.271±0.091 vs. 0.104±0.012 mm×m²/ml, mean±SD, p<0.001). Mitral lateral annulus e' velocity referred to diastolic dysfunction in HCM (15.3±3.6 vs. 7.9±3.3 vs. 15.0±3.0 cm/s, p<0.01). At time point of mitral valve opening, untwist and untwist rate were significantly different: the highest values were measured in athletes, while the lowest were found in HCM (untwist: 51.3±19.1 vs. 11.6±10.4 vs. 35.9±16.3%; untwist rate: -32.5±13.0 vs. -10.6±10.8 vs. -23.0±7.7°/s, p<0.05). Untwisting correlated with E/A, e' and E/e'. Athlete's heart is characterized by increased untwist and untwist rate, which can aid diastolic function. Evaluation of untwisting dynamics may help to distinguish pathological hypertrophy.

Serum fetuin-A levels inversely correlate with the severity of arterial calcification in patients with chronic lower extremity atherosclerosis without renal disease.

AIM: Fetuin-A is a hepatic glycoprotein that inhibits extraosseous calcification. Lower serum fetuin-A concentration was associated with severe arterial calcification in patients with end stage renal disease. We evaluated the association of serum fetuin-A levels and the severity of atherosclerosis in patients with peripheral vascular disease having normal renal function. METHODS: In this cross-sectional study among 93 chronic atherosclerotic patients with lower extremity vascular disease, systemic atherosclerosis and calcification was assessed by ultrasound (carotid intima-media thickness/IMT/, calcification at the abdominal aorta, carotid and femoral bifurcations, aortic and mitral valves) and angiography (Bollinger score). Standard serum markers of inflammation, diabetes, renal function, ankle-brachial indexes and traditional risk factors for atherosclerosis were noted and Fontaine classification was applied for the severity of symptoms. RESULTS: The patients mean (SD) age was 59.95 (7.61) years, 78% were men, 35% had diabetes. Serum fetuin-A level showed significant negative correlation with ultrasound calcification score (P=0.018, r=-0.257) and Bollinger angiographic score (P=0.035, r=-0.347). Fetuin-A did not correlate with IMT or Fontaine classification. Fetuin-A also showed significant correlation with albumin, transferrin and hemoglobin A1c (r=0.287, 0.305 and 0.219, respectively at P<0.05). Logistic regression analysis confirmed the association between fetuin-A and calcification score (OR: 3.03, CI: 1.05-8.7), P=0.039) independent of traditional risk factors. CONCLUSION: Our data show that serum fetuin-A levels inversely correlate with the severity of atherosclerosis in nonuremic patients with symptomatic chronic lower limb ischemia. These data support a putative protective role for fetuin-A in the development of arterial calcification.

Depressed activation of the lectin pathway of complement in hereditary angioedema.

The possibility of simultaneous measurement of the classical pathway (CP), mannan-binding lectin (MBL)--lectin pathway (LP) and alternative pathway (AP) of complement activation by the recently developed Wielisa method allowed us to investigate the in vivo significance of the C1-inhibitor (C1INH) in three complement activation pathways. Functional activity of the CP, LP and AP were measured in the sera of 68 adult patients with hereditary angioedema (HAE) and 64 healthy controls. In addition, the level of C1q, MBL, MBL-associated serine protease-2 (MASP-2), C4-, C3- and C1INH was measured by standard laboratory methods. MBL-2 genotypes were determined by polymerase chain reaction. Besides the complement alterations (low CP and C1INH activity, low C4-, C1INH concentrations), which characterize HAE, the level of MASP-2 was also lower (P = 0.0001) in patients compared with controls. Depressed LP activity was found in patients compared with controls (P = 0.0008) in homozygous carriers of the normal MBL genotype (A/A), but not in carriers of variant genotypes (A/O, O/O). Activity of CP correlated with LP in patients (Spearman's r = 0.64; P < 0.0001), but no significant correlation was found in the control group and no correlation with AP was observed. In contrast, the activity of CP and AP correlated (Spearman's r = 0.47; P < 0.0001) in healthy controls, but there was no significant correlation in the HAE patients. We conclude that the activation of LP might also occur in subjects with C1INH deficiency, which is reflected by the low MASP-2 and C4 levels.