Ahmet Adiyaman

Blood pressure changes after renal denervation at 10 European expert centers

We did a subject-level meta-analysis of the changes (Δ) in blood pressure (BP) observed 3 and 6 months after renal denervation (RDN) at 10 European centers. Recruited patients (n=109; 46.8% women; mean age 58.2 years) had essential hypertension confirmed by ambulatory BP. From baseline to 6 months, treatment score declined slightly from 4.7 to 4.4 drugs per day. Systolic/diastolic BP fell by 17.6/7.1 mm Hg for office BP, and by 5.9/3.5, 6.2/3.4, and 4.4/2.5 mm Hg for 24-h, daytime and nighttime BP (P⩽0.03 for all). In 47 patients with 3- and 6-month ambulatory measurements, systolic BP did not change between these two time points (P⩾0.08). Normalization was a systolic BP of <140 mm Hg on office measurement or <130 mm Hg on 24-h monitoring and improvement was a fall of ⩾10 mm Hg, irrespective of measurement technique. For office BP, at 6 months, normalization, improvement or no decrease occurred in 22.9, 59.6 and 22.9% of patients, respectively; for 24-h BP, these proportions were 14.7, 31.2 and 34.9%, respectively. Higher baseline BP predicted greater BP fall at follow-up; higher baseline serum creatinine was associated with lower probability of improvement of 24-h BP (odds ratio for 20-μmol l−1 increase, 0.60; P=0.05) and higher probability of experiencing no BP decrease (OR, 1.66; P=0.01). In conclusion, BP responses to RDN include regression-to-the-mean and remain to be consolidated in randomized trials based on ambulatory BP monitoring. For now, RDN should remain the last resort in patients in whom all other ways to control BP failed, and it must be cautiously used in patients with renal impairment.

Determinants of the Ambulatory Arterial Stiffness Index in 7604 Subjects From 6 Populations

The ambulatory arterial stiffness index (AASI) is derived from 24-hour ambulatory blood pressure recordings. We investigated whether the goodness-of-fit of the AASI regression line in individual subjects (r2) impacts on the association of AASI with established determinants of the relation between diastolic and systolic blood pressures. We constructed the International Database on the Ambulatory Blood Pressure in Relation to Cardiovascular Outcomes (7604 participants from 6 countries). AASI was unity minus the regression slope of diastolic on systolic blood pressure in individual 24-hour ambulatory recordings. AASI correlated positively with age and 24-hour mean arterial pressure and negatively with body height and 24-hour heart rate. The single correlation coefficients and the mutually adjusted partial regression coefficients of AASI with age, height, 24-hour mean pressure, and 24-hour heart rate increased from the lowest to the highest quartile of r2. These findings were consistent in dippers and nondippers (night:day ratio of systolic pressure ≥0.90), women and men, and in Europeans, Asians, and South Americans. The cumulative z score for the association of AASI with these determinants of the relation between diastolic and systolic blood pressures increased curvilinearly with r2, with most of the improvement in the association occurring above the 20th percentile of r2 (0.36). In conclusion, a better fit of the AASI regression line enhances the statistical power of analyses involving AASI as marker of arterial stiffness. An r2 value of 0.36 might be a threshold in sensitivity analyses to improve the stratification of cardiovascular risk.

Renal Nerve Stimulation-Induced Blood Pressure Changes Predict Ambulatory Blood Pressure Response After Renal Denervation

Blood pressure (BP) response to renal denervation (RDN) is highly variable and its effectiveness debated. A procedural end point for RDN may improve consistency of response. The objective of the current analysis was to look for the association between renal nerve stimulation (RNS)–induced BP increase before and after RDN and changes in ambulatory BP monitoring (ABPM) after RDN. Fourteen patients with drug-resistant hypertension referred for RDN were included. RNS was performed under general anesthesia at 4 sites in the right and left renal arteries, both before and immediately after RDN. RNS-induced BP changes were monitored and correlated to changes in ambulatory BP at a follow-up of 3 to 6 months after RDN. RNS resulted in a systolic BP increase of 50±27 mm Hg before RDN and systolic BP increase of 13±16 mm Hg after RDN (P<0.001). Average systolic ABPM was 153±11 mm Hg before RDN and decreased to 137±10 mm Hg at 3- to 6-month follow-up (P=0.003). Changes in RNS-induced BP increase before versus immediately after RDN and changes in ABPM before versus 3 to 6 months after RDN were correlated, both for systolic BP (R=0.77, P=0.001) and diastolic BP (R=0.79, P=0.001). RNS-induced maximum BP increase before RDN had a correlation of R=0.61 (P=0.020) for systolic and R=0.71 (P=0.004) for diastolic ABPM changes. RNS-induced BP changes before versus after RDN were correlated with changes in 24-hour ABPM 3 to 6 months after RDN. RNS should be tested as an acute end point to assess the efficacy of RDN and predict BP response to RDN.

Interstudy Variability in the Ambulatory Arterial Stiffness Index

To the Editor: In 2006, Li et al1 proposed the ambulatory arterial stiffness index (AASI) as a novel marker for arterial stiffness. AASI is derived from the linear relationship between systolic blood pressure and diastolic blood pressure observed using 24-hour ambulatory blood pressure monitoring. The literature published on this topic shows some large differences in the mean AASI between studies. In our opinion, these differences cannot be fully accounted for by differences in methodology and patient characteristics. The Table shows a review of important issues of methodology and …

Myocardial scar characteristics based on cardiac magnetic resonance imaging is associated with ventricular tachyarrhythmia in patients with ischemic cardiomyopathy

OBJECTIVES We hypothesized that myocardial scar characterization using cardiac magnetic resonance imaging (CMR) may be associated with the occurrence of ventricular tachyarrhythmia (VT), appropriate implantable cardioverter-defibrillator (ICD) therapy and mortality. BACKGROUND Since a minority of patients with prophylactic ICD implantation receive appropriate ICD therapy, there is a need for more effective risk stratification for primary prevention in patients with ischemic cardiomyopathy. METHODS AND RESULTS In 99 patients with ischemic cardiomyopathy, CMR was performed prior to ICD implantation. We assessed if CMR indices (cardiac mass, LVEF) and CMR scar characteristics (infarct core mass, peri-infarction mass and the ratios between left ventricular mass, infarct core mass and peri-infarction mass) were associated with outcome. The primary endpoint was sustained VT and/or appropriate ICD therapy. The secondary endpoint was all-cause mortality. During a median follow-up of 5.4 years (IQR 4.5-6.6 years), 34 patients reached the primary end-point (17 appropriate ICD shocks) and 26 patients died. In multivariable Cox regression analysis, peri-infarction to core-infarction ratio (HR 2.01, 95%CI: 1.17-3.44, p=0.01) was independently and significantly associated with the primary endpoint, whereas NYHA-class and lower LVEF were not. Conversely, age (HR 1.06, 95% CI: 1.01-1.12, p=0.02) and lower LVEF (HR 0.95, 95% CI: 0.91-1.00, p=0.04) were independently associated with all-cause mortality, mainly due to heart failure. CONCLUSION A relatively large peri-infarction mass is associated with sustained VT and/or appropriate ICD therapy, whereas age and lower LVEF are associated with mortality. CMR based tissue characterization could aid in the prediction of specific outcome measures and in clinical decision making.

The effect of crossing legs on blood pressure.

ObjectiveTo determine whether crossing of the legs at the knee or at the ankles during blood pressure measurement in sitting position has an effect on blood pressure. MethodsOne hundred and eleven patients, 60 women, mean age 52±17 years (19–80): 49 chronically treated hypertensives, 28 treated diabetics and 34 normotensives were measured by one trained investigator, with an oscillometric device (Omron 705CP) on the left arm. We looked for the difference of blood pressure with the ankle or the knee crossed versus the uncrossed position. ResultsLeg crossing at the knee during blood pressure measurement increased systolic blood pressure significantly by 6.7 (95% confidence interval 5.0–8.4) mmHg in the hypertensives and 7.9 (4.0–11.8) mmHg in the treated diabetics. Diastolic blood pressure increased by 2.3 (0.8–3.8) mmHg in the hypertensives and 1.7 (0.1–3.4) mmHg for the treated diabetics. Normotensive participants showed a smaller, though significant, increase of systolic blood pressure 2.7 (1.2–4.2) mmHg, but not significant for diastolic blood pressure, −0.1 (−1.5–1.3) mmHg, respectively. In all groups there was no effect of crossing the ankles on blood pressure. No differences were found between men and women. No significant correlation between the increase of the blood pressure when the knees were crossed and BMI, age or baseline blood pressure was present. ConclusionsBlood pressure increased when legs were crossed at the knee in the sitting position. No significant increase of blood pressure was found when crossing the legs at the ankles. Leg position during measurement of blood pressure should be standardized and mentioned in publications.

Ablation of focal atrial tachycardia from the non-coronary aortic cusp: case series and review of the literature

AIMS Focal atrial tachycardia successfully ablated from the non-coronary cusp (NCC) is rare. Our aim was to describe the characteristics of mapping and ablation therapy of NCC focal atrial tachycardias and to provide a comprehensive review of the literature. METHODS AND RESULTS Seven patients (age 40 ± 9 years) with symptomatic, drug-refractory atrial tachycardia were referred for electrophysiological study. Extensive right and left atrial mapping revealed atrial tachycardia near His in all patients but either failed to identify a successful ablation site or radiofrequency applications only resulted in temporary termination of the tachycardia. Mapping and ablation of the NCC were performed retrogradely via the right femoral artery. Mapping of the NCC demonstrated earliest atrial activation during atrial tachycardia 38 ± 14 ms (ranging 17-56 ms) before the onset of the P-wave. Earliest atrial activation in the NCC was earlier than earliest activation in the right atrium and left atrium in all patients. The P-wave morphology was predominantly negative in the inferior leads and biphasic in leads V1 and V2. The tachycardia was successfully terminated by radiofrequency application in 10 ± 6 s (2-16 s), without complications. All patients were free of symptoms during a follow-up of 19 ± 9 months. Literature search revealed 18 reports (91 patients) describing NCC focal atrial tachycardia, with 99% long-term ablation success with a 1% complication rate. CONCLUSION Symptomatic focal atrial tachycardia near His may originate from the NCC and can be treated safely and effectively with radiofrequency ablation.

Persistent Increase in Blood Pressure After Renal Nerve Stimulation in Accessory Renal Arteries After Sympathetic Renal Denervation

Blood pressure response to renal denervation is highly variable, and the proportion of responders is disappointing. This may be partly because of accessory renal arteries too small for denervation, causing incomplete ablation. Renal nerve stimulation before and after renal denervation is a promising approach to assess completeness of renal denervation and may predict blood pressure response to renal denervation. The objective of the current study was to assess renal nerve stimulation–induced blood pressure increase before and after renal sympathetic denervation in main and accessory renal arteries of anaesthetized patients with drug-resistant hypertension. The study included 21 patients. Nine patients had at least 1 accessory renal artery in which renal denervation was not feasible. Renal nerve stimulation was performed in the main arteries of all patients and in accessory renal arteries of 6 of 9 patients with accessory arteries, both before and after renal sympathetic denervation. Renal nerve stimulation before renal denervation elicited a substantial increase in systolic blood pressure, both in main (25.6±2.9 mm Hg; P<0.001) and accessory (24.3±7.4 mm Hg; P=0.047) renal arteries. After renal denervation, renal nerve stimulation–induced systolic blood pressure increase was blunted in the main renal arteries (&Dgr; systolic blood pressure, 8.6±3.7 mm Hg; P=0.020), but not in the nondenervated renal accessory renal arteries (&Dgr; systolic blood pressure, 27.1±7.6 mm Hg; P=0.917). This residual source of renal sympathetic tone may result in persistent hypertension after ablation and partly account for the large response variability.

Dipping Deeper Into the Ambulatory Arterial Stiffness Index

To the Editor: Methodologic and conceptual issues seriously weaken the conclusions of Schillaci et al1 on the ambulatory arterial stiffness index (AASI), as published in the May 2007 issue of Hypertension . Schillaci et al1 reported that, in 515 untreated patients, AASI depended on the nocturnal blood pressure fall. We confirmed this observation in our Flemish population study.2 The correlation coefficients were similar to those in the report by Schillaci et al1: −0.24 versus −0.28 for systolic blood pressure (2-sided P value computed by Fisher’s Z transformation, 0.42), and −0.39 versus −0.46 for diastolic blood pressure ( P =0.11). However, the ambulatory recording of 1 of the representative patients of Schillaci et al1 included ≈25 nighttime and ≈35 daytime readings. The night:day ratio of the number …

Conventional radiofrequency catheter ablation compared to multi-electrode ablation for atrial fibrillation

BACKGROUND Limited data is available on long-term atrial fibrillation (AF) free survival after multi-electrode catheter pulmonary vein isolation (PVI). The aim of this study was to compare point-by-point PVI to multi-electrode PVI in terms of procedural characteristics and long-term AF free survival. METHODS AND RESULTS 460 consecutive patients were randomly allocated: 230 patients underwent conventional, point-by-point ablation with a radiofrequency ablation catheter (cPVI group) and 230 patients underwent multi-electrode, phased radiofrequency ablation (MER group). Median follow-up was 43 months. Mean age was 56 years, 82% of patients had paroxysmal AF. Baseline characteristics did not differ among catheter groups. Acute electrical PVI was achieved in 99.7% of pulmonary veins, with no differences among catheter groups. Procedure time and ablation time were significantly shorter in the MER group. There were significantly less complications in the MER group (4.8% vs. 1.3%, P=0.025). After a mean of 1.5 procedures, AF free survival without the use of antiarrhythmic drugs was 74% at 1 year and 46% at 5 years follow-up and did not differ among catheter groups (cPVI group 45%, MER group 48%, P=0.777). In multivariate analysis, BMI, AF duration and CHADSVASc score were predictors of AF free survival. CONCLUSION Multi-electrode ablation was superior in procedure duration and ablation time, with less complications. However, both conventional point-by-point PVI and multi-electrode PVI achieved a high acute PVI success rate and showed a comparable long-term AF free survival.