Ioannis H. Styliadis

Left Ventricular Outflow Tract Obstruction as a Risk Factor for Sudden Cardiac Death in Hypertrophic Cardiomyopathy

The effect of left ventricular outflow tract obstruction (LVOTO) at rest on the incidence of sudden death (SD) in patients with hypertrophic cardiomyopathy is rather conflicting. The aim of this study was the evaluation of LVOTO at rest as a new potential risk factor for SD in hypertrophic cardiomyopathy. A total of 166 patients (112 men, 51.8 +/- 15.6 years) were studied; 50 patients (30.1%) had peak instantaneous LVOTO gradients of > or = 30 mm Hg at rest. During the follow-up period (median 32.4 months, range 1 to 209), 13 patients either died suddenly, or had cardiac arrest, documented sustained ventricular tachycardia, or implantable cardioverter defibrillator discharge. The cumulative event-free survival rate was 92% in patients with LVOTO, and 92% in patients without obstruction (p = NS). LVOTO at rest was associated with a particularly low positive predictive value for SD (8%), although a high negative predictive value (92%) was recorded. Patients having syncope or presenting with a maximum wall thickness > or =3 cm in echocardiography were more sensitive to SD emergence because they had a 13.07 (95% confidence interval 4.00 to 46.95, p <0.0001) and a 10.07 (95% confidence interval 2.92 to 34.79, p = 0.003) greater relative risk, respectively. In conclusion, our cohort study results do not support LVOTO as an independent risk factor for SD in patients with hypertrophic cardiomyopathy.

Radial versus femoral access for orally anticoagulated patients

Objectives: To prospectively compare the efficacy and procedural safety of the radial versus femoral route for cardiac catheterization during uninterrupted warfarin therapy. Background: The optimal treatment strategy for cardiac catheterization in patients receiving long‐term oral anticoagulation has not been defined. Increasing evidence suggests the feasibility and safety of catheterization without warfarin interruption. However, the relative safety and efficacy of the radial and femoral access in fully anticoagulated patients are unknown. Methods: Fifty‐six consecutive patients on chronic warfarin treatment with international normalized ratio (INR) between 1.8 and 3.5 were randomized to undergo coronary angiography, alone, or followed by percutaneous coronary intervention (PCI), via the femoral (n = 29) or radial route (n = 27). Procedural success, in‐hospital major adverse cardiac and cerebrovascular events, access‐site, and bleeding complications were recorded. Results: The two groups were well balanced with similar clinical characteristics at baseline. There were no significant differences in preprocedural antiplatelet therapy or in INR levels between the radial and femoral group (2.62 ± 0.7 vs. 2.48 ± 0.6, respectively, P = 0.63). Procedural success was achieved in all femoral patients, whereas one patient in the radial group (3.7%) required crossover to femoral access. Eight patients from the femoral and 10 patients from the radial group successfully underwent PCI. Access‐site complications occurred only in patients who underwent PCI: three (37.5%) in the femoral versus none in the radial group (P = 0.034). Conclusion: The radial access is as efficacious and safe as the femoral route for coronary angiography in fully anticoagulated patients, but is likely to result in fewer access‐site complications in patients who also undergo PCI.

Transulnar Compared With Transradial Artery Approach as a Default Strategy for Coronary Procedures A Randomized Trial The Transulnar or Transradial Instead of Coronary Transfemoral Angiographies Study (The AURA of ARTEMIS Study)

Background—The ulnar artery is rarely selected for coronary angiography or percutaneous coronary intervention despite the expanding use of the transradial approach. We aimed to establish noninferiority of a default transulnar relative to transradial approach in terms of feasibility and safety. Methods and Results—This was a prospective, randomized, multicenter, parallel-group study involving 902 patients at 5 sites eligible to undergo diagnostic coronary angiography and percutaneous coronary intervention. Patients were randomized in a 1:1 ratio to either transradial approach (reference intervention) or transulnar approach (experimental intervention) regardless of the Allen test results. The primary end point was a composite of cross-over to another arterial access, major adverse cardiovascular events, and major vascular events of the arm at 60 days. The study was prematurely terminated after the first interim analysis because of inferiority of the transulnar approach. Although the difference in the primary end point became inconclusive after adjustment for operator clustering (24.30%; 99.99% confidence interval [CI], −7.98% to 56.58%; P=0.03 at &agr;=0.0001), need for cross-over in the transulnar group remained inferior to transradial access site with a difference of 26.34% (95% CI, 11.96%–40.69%; P=0.004). Conclusions—As a result of higher cross-over rates, a first-line transulnar strategy was proven inferior to the transradial approach for coronary procedures. At present, the transulnar route should not be regarded as an acceptable alternative to the transradial access site. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01364532.

Novel non-invasive P wave analysis for the prediction of paroxysmal atrial fibrillation recurrences in patients without structural heart disease: A prospective pilot study

OBJECTIVES The pathogenetic mechanisms responsible for the initiation and recurrence of PAF are not fully elucidated and vary among individuals. We evaluated the ability of a novel non-invasive approach based on P wave wavelet analysis to predict symptomatic paroxysmal atrial fibrillation (PAF) recurrences in individuals without structural heart disease. METHODS We studied 50 patients (24 males, mean age 54.9 ± 9.8 years) presented to our emergency department with a symptomatic episode of PAF. The patients were followed-up for 12.1 ± 0.1 months and classified into two groups according to the number of PAF episodes: Group A (<5 PAF, n = 33), Group B (≥ 5 PAF, n = 17). A third Group of 50 healthy individuals without history of PAF was used as control. Study groups underwent echocardiography and orthogonal ECG-based wavelet analyses of P waves at baseline and follow-up. Maximum and mean P wave energies were calculated in each subject at each orthogonal lead using the Morlet wavelet analysis. RESULTS Larger P wave energies at X lead and relatively larger left atrium were independently associated with >5 PAF episodes vs. <5 PAF episodes. No difference in P wave duration was detected between Groups A and B (p > 0.1), whereas Group A and B patients had longer P waves at Z lead compared to Group C (86.4 ± 13 vs. 71.5 ± 15 msec, p < 0.001). CONCLUSIONS P wave wavelet analysis can reliably predict the generation and recurrence of PAF within a year. P wave wavelet analysis could contribute to the early identification of patients at risk for increased number of PAF recurrences.

Chronotropic incompetence and its relation to exercise intolerance in hypertrophic cardiomyopathy.

BACKGROUND Diminished functional capacity is common in hypertrophic cardiomyopathy (HCM), although the underlying mechanisms are complicated. We studied the prevalence of chronotropic incompetence and its relation to exercise intolerance in patients with HCM. METHODS Cardiopulmonary exercise testing was performed in 68 patients with HCM (age 44.8 ± 14.6 years, 45 males). Chronotropic incompetence was defined by chronotropic index (heart rate reserve)/(220-age-resting heart rate) and exercise capacity was assessed by peak oxygen consumption (peak Vo(2)). RESULTS Chronotropic incompetence was present in 50% of the patients and was associated with higher NYHA class, history of atrial fibrillation, higher fibrosis burden on cardiac MRI, and treatment with β-blockers, amiodarone and warfarin. On univariate analysis, male gender, age, NYHA class, maximal wall thickness, left atrial diameter, peak early diastolic myocardial velocity of the lateral mitral annulus, history of atrial fibrillation, presence of left ventricular outflow tract obstruction (LVOTO) at rest, and treatment with beta-blockers were related to peak Vo(2). Peak heart rate during exercise, heart rate reserve, chronotropic index, and peak systolic blood pressure were also related to peak Vo(2). On multivariate analysis male gender, atrial fibrillation, presence of LVOTO and heart rate reserve were independent predictors of exercise capacity (R(2) = 76.7%). A cutoff of 62 bpm for the heart rate reserve showed a negative predictive value of 100% in predicting patients with a peak Vo(2) <80%. CONCLUSIONS Blunted heart rate response to exercise is common in HCM and represents an important determinant of exercise capacity.

Left ventricular function in elite rowers in relation to training‐induced structural myocardial adaptation

To examine left ventricular (LV) function in elite young athletes in relation to structural adaptation to prolonged intense training. Conventional echocardiography and tissue Doppler imaging (TDI) were performed in 15 elite rowers and 12 sedentary matched controls. Rowers had increased LV mass index, septal (12 vs 10 mm, P<0.005) and posterior wall thicknesses (12 vs 9 mm, P<0.001) and increased relative wall thickness. Septal and lateral systolic velocities were enhanced in rowers (septal Sm=8.5 vs 6.3 cm/s, P<0.001; lateral Sm=11.4 vs 8.0 cm/s, P<0.005), representing a 35% and 42% increase, respectively. Similarly, septal and lateral early diastolic velocities were enhanced (septal Em=12.1 vs 9.5 cm/s, P<0.01; lateral Em=16.6 vs 11.6 cm/s, P<0.001), representing a 27% and 43% increase, respectively. Systolic and early diastolic TDI velocities of the lateral wall showed a positive correlation (r=0.65, P<0.01) in athletes indicating a parallel improvement of systolic and diastolic function, while LV stiffness was decreased [(E/Em)/(LV end‐diastolic diameter)=1.13 vs 1.57, P<0.005). Both systolic and diastolic LV function were improved in elite rowers, despite a pattern of concentric hypertrophy.

Spontaneous Dissection of Right Coronary Artery Manifested with Acute Myocardial Infarction

Spontaneous coronary artery dissection is a rare cause of acute ischemic coronary events and sudden cardiac death. It usually occurs in young women without traditional risk factors for coronary artery disease during pregnancy or postpartum period. However, it has also been reported in patients with atherosclerotic coronary disease. We present a case of spontaneous right coronary artery dissection in a 48-year male with recent myocardial infarction and previous percutaneous coronary intervention.

QRS analysis using wavelet transformation for the prediction of response to cardiac resynchronization therapy: a prospective pilot study.

BACKGROUND Wider QRS and left bundle branch block morphology are related to response to cardiac resynchronization therapy (CRT). A novel time-frequency analysis of the QRS complex may provide additional information in predicting response to CRT. METHODS Signal-averaged electrocardiograms were prospectively recorded, before CRT, in orthogonal leads and QRS decomposition in three frequency bands was performed using the Morlet wavelet transformation. RESULTS Thirty eight patients (age 65±10years, 31 males) were studied. CRT responders (n=28) had wider baseline QRS compared to non-responders and lower QRS energies in all frequency bands. The combination of QRS duration and mean energy in the high frequency band had the best predicting ability (AUC 0.833, 95%CI 0.705-0.962, p=0.002) followed by the maximum energy in the high frequency band (AUC 0.811, 95%CI 0.663-0.960, p=0.004). CONCLUSIONS Wavelet transformation of the QRS complex is useful in predicting response to CRT.

Patients with hypertrophic cardiomyopathy at risk for paroxysmal atrial fibrillation: advanced echocardiographic evaluation of the left atrium combined with non-invasive P-wave analysis

AIMS The maintenance of sinus rhythm is crucial for the functional capacity of patients with hypertrophic cardiomyopathy (HCM). Using a multimodality approach, we attempted to identify potential predictors of paroxysmal atrial fibrillation (PAF) in HCM patients. METHODS AND RESULTS Thirty HCM patients (17 males, mean age 57.9 ± 13.6) with at least one documented PAF episode and 32 age- and sex-matched HCM control patients as well as 25 healthy volunteers were studied in sinus rhythm. Study subjects underwent 2D echocardiography including a colour Doppler myocardial imaging evaluation of the left atrium (LA). Additionally, an orthogonal electrocardiogram was acquired; P-wave duration, maximum, and mean energies were calculated for each subject at each orthogonal lead and the composite vector axis using the Morlet wavelet analysis. Compared with HCM controls, in HCM-PAF patients, LA antero-posterior diameter was significantly enlarged (LADAP: 46.1 ± 5.9 vs. 40.0 ± 4.7 mm, P < 0.001), peak strain rate of the LA lateral wall in the reservoir phase was significantly decreased (LAT peak SR-S: 1.93 ± 0.51 vs. 2.55 ± 0.83 s(-1), P < 0.01), and P-wave duration in the Z-lead was significantly prolonged (P-durZ: 106.9 ± 24.6 vs. 86.2 ± 14.3 ms, P < 0.001). Cut-off values and areas under the curve (AUCs) for individual parameters were 42.0 mm, 2.32 s(-1), and 98.8 ms and 0.81, 0.74, and 0.78, respectively. A multivariable model combining LADAP, LAT peak SR-S and P-durZ had an AUC of 0.90, a sensitivity of 0.87, and a specificity of 0.91 for identifying PAF patients. CONCLUSION P-wave duration combined with LA antero-posterior diameter and myocardial deformation indices resulted in a higher power for discriminating HCM-PAF patients, when compared with individual parameters derived from either wavelet analysis or 2D echocardiography.

Effects of renin–angiotensin system inhibition on right ventricular function in patients with mild essential hypertension

Introduction: Systemic hypertension is known to affect both left and right ventricular (RV) function. Little is known about the effect of the renin—angiotensin system (RAS) inhibition on global RV function in patients with essential hypertension. Materials and methods: Forty patients (17 male, mean age 47 ± 10 years) with mild hypertension free of cardiovascular disease were assessed by echocardiography at baseline and after nine months of antihypertensive treatment with RAS inhibitors. Tissue Doppler imaging derived myocardial performance index (MPI) of the left and right ventricle was used as an index of global ventricular function. Results: Both left ventricular (LV) and RV MPI were increased at baseline and were reduced after treatment (LV MPI reduced from 0.42 ± 0.06 to 0.39 ± 0.05, p < 0.001 and RV MPI was reduced from 0.34 ± 0.06 to 0.32 ± 0.05, p < 0.005). There was a positive correlation between mitral and tricuspid E/A ratio both at baseline and at month nine after treatment (r = 0.661, p < 0.001 and r = 0.503, p < 0.005 respectively). LV mass index and interventricular septum thickness were decreased after treatment. No correlation was found between MPI improvement and blood pressure reduction. Conclusions: RAS inhibition in patients with mild hypertension results in an improvement of RV global function which is unrelated to the reduction in blood pressure.