[show abstract][hide abstract] ABSTRACT: It has been suggested that corrected QT dispersion (cQTD) provides a measure of repolarisation inhomogeneity; however, the existence of a relationship between cQTD and cardiac outcomes is controversial.
To assess whether changes in cQTD following percutaneous coronary intervention (PCI) predict long-term survival.
Prospective observational study.
Single tertiary care centre. Main outcome measures Cardiac mortality.
612 patients had a 12-lead ECG recorded before and 6 h after PCI, and were followed-up for 49 ± 10 months.
PCI was associated with a significant overall reduction of cQTD at 6 h versus baseline (p < 0.001); a reduction in cQTD occurred in 343 patients (56%). During the follow-up, 46 deaths (7.5%) were recorded, 21 of which for non-cardiac and 25 for cardiac causes. At Cox regression analysis, a reduced ΔcQTD (cQTD baseline - 6 h) was an independent predictor of cardiac mortality (HR = 1.497; 95% CI 1.081 to 2.075 for each 20 ms decrease; p = 0.015), together with age (HR = 1.672; 95% CI 1.039 to 2.691 per 10 years increase; p = 0.034), diabetes (HR = 2.622; 95% CI 1.112 to 6.184; p=0.028), peak CK-MB (HR = 1.798; 95% CI 1.063 to 3.039 per each unit increase over normal level; p = 0.029), three-vessel coronary artery disease (HR=3.626; 95% CI 1.079 to 12.187; p = 0.037) and the number of treated lesions (HR=2.066; 95% CI 1.208 to 3.532; p = 0.008). Patients in the lowest tertile of ΔcQTD and having a post-procedural increase of CK-MB had a considerably higher cardiac mortality than the remaining population (14.6 vs 2.4%, p < 0.001).
cQTD decreases after PCI. A defective cQTD recovery, suggesting the persistence of repolarisation inhomogeneities, predicts long-term cardiac mortality.
[show abstract][hide abstract] ABSTRACT: Biventricular (BiV) pacing is an established therapy for heart failure in ischaemic and dilated cardiomyopathy. Its effects in end-stage hypertrophic cardiomyopathy (HCM) are unknown.
To assess the potential benefits of BiV pacing in patients with symptomatic end-stage HCM.
Twenty patients with non-obstructive HCM (12 male, mean age 57+/-13 years), left bundle branch block and symptoms of heart failure refractory to medical therapy underwent implantation of a BiV device. NYHA class, echocardiographic parameters and exercise capacity were assessed before and after implantation.
At a mean follow-up of 13+/-6 months, an improvement of at least one NYHA class was reported in 8 (40%) patients. A clinical response was associated with an increase in ejection fraction (from 41+/-14% to 50+/-12%, p=0.009), and reductions in left ventricular end-diastolic diameter (from 57+/-6 mm to 52+/-7 mm, p=0.031) and left atrial diameter (from 65+/-8 mm to 57+/-6 mm, p=0.005). Percentage predicted peak oxygen consumption was unchanged in responders but significantly declined in non-responders (p=0.029).
BiV pacing improved heart failure symptoms in a significant proportion of patients with end-stage HCM. Symptomatic improvement was associated with reverse remodelling of the left atrium and ventricle.
European Journal of Heart Failure 06/2008; 10(5):507-13. · 5.25 Impact Factor
[show abstract][hide abstract] ABSTRACT: A common problem in diagnostic medicine, when performing a diagnostic test, is to obtain an accurate discrimination between 'normal' cases and cases with disease, owing to the overlapping distributions of these populations. In clinical practice, it is exceedingly rare that a chosen cut point will achieve perfect discrimination between normal cases and those with disease, and one has to select the best compromise between sensitivity and specificity by comparing the diagnostic performance of different tests or diagnostic criteria available. Receiver operating characteristic (or receiver operator characteristic, ROC) curves allow systematic and intuitively appealing descriptions of the diagnostic performance of a test and a comparison of the performance of different tests or diagnostic criteria. This review will analyse the basic principles underlying ROC curves and their specific application to the choice of optimal parameters on exercise electrocardiographic stress testing. Part II will be devoted to the comparative analysis of various parameters derived from exercise stress testing for the diagnosis of underlying coronary artery disease.
Journal of Cardiovascular Medicine 02/2008; 9(1):22-31. · 2.66 Impact Factor
[show abstract][hide abstract] ABSTRACT: A common problem in diagnostic medicine, when performing a diagnostic test, is to obtain an accurate discrimination between 'normal' cases and cases with disease, owing to the overlapping distributions of these populations. In clinical practice, it is exceedingly rare that a chosen cut point will achieve perfect discrimination between normal cases and those with disease, and one has to select the best compromise between sensitivity and specificity by comparing the diagnostic performance of different tests or diagnostic criteria available. Receiver operating characteristic (or receiver operator characteristic, ROC) curves allow systematic and intuitively appealing descriptions of the diagnostic performance of a test and a comparison of the performance of different tests or diagnostic criteria. This review will analyse the basic principles underlying ROC curves and their specific application to the choice of optimal parameters on exercise electrocardiographic (ECG) stress testing. Part I will focus on theoretical description and analysis along with reviewing the common problems related to the diagnosis of myocardial ischaemia by means of exercise ECG stress testing. Part II will be devoted to applying ROC curves to available diagnostic criteria through the analysis of ECG stress test parameters.
Journal of Cardiovascular Medicine 12/2007; 8(11):873-81. · 2.66 Impact Factor
[show abstract][hide abstract] ABSTRACT: QT dispersion (QTd) is the difference between the maximum and the minimum QT interval in the 12-lead ECG. There is currently no information on the relationship between QTd and creatine kinase (CK)-MB release in patients undergoing percutaneous coronary intervention (PCI).
Among 118 patients undergoing successful PCI stenting, QTd and corrected QTd (QTdc) were measured at standard 12-lead ECG before PCI and at 6 and 18 hours after PCI. The median of QTdc variation (deltaQTdc = baseline QTdc - QTdc at 6 hours) was 9.5 ms (range -48 / +89 ms). Patients were divided into two groups according to deltaQTdc: group A "recoverers" (deltaQTdc > 9.5 ms, n = 59, 50%), group B "non-recoverers" (deltaQTdc < 9.5 ms, n = 59, 50%). CK-MB release was compared in the two groups.
Eighty-three percent of patients were male, with mean age of 62 years (range 41-80 years). Unstable angina was present in 35% of cases, with similar distribution in the two groups. PCI was performed in 1.94 lesions/patient with the implantation of 1.6 stent/patient. Compared to baseline, a reduction in both QTc and QTdc was documented at 6 and 18 hours after PCI (p < 0.05). Periprocedural variations (CK-MB > 2 upper limit of normal) was detected in 4 patients (7%) of group A and 12 patients (20%) in group B (p = 0.06). Peak CK-MB release was significantly lower in group A (13 +/- 14.3 IU/l) compared to group B (23.2 +/- 35 IU/l, p < 0.05).
After successful coronary stenting there is a rapid normalization of QTd and QTdc. The lack of recovery of both QTd and QTdc is related to minor elevations of CK-MB and may therefore be further explored as a useful non-invasive marker of heterogeneous reperfusion after PCI.
Italian heart journal. Supplement: official journal of the Italian Federation of Cardiology 11/2004; 5(11):861-7.
[show abstract][hide abstract] ABSTRACT: Treatment of in-stent restenosis is still a challenge. Despite promising results obtained with intracoronary brachytherapy (ICB), the ideal strategy of device selection has not been identified. The aim of this study was to evaluate the influence of device selection on ICB for the treatment of instant restenosis.
The outcomes of 130 patients from the Washington Radiation for In-Stent restenosis Trial (WRIST) were studied. Patients were analyzed on the basis of device selection, prior to randomization to gamma-radiation (n = 65) or placebo (n = 65): balloon angioplasty (PTCA) (n = 15, 12%), rotational atherectomy (RA) (n = 40, 31%), excimer laser coronary angioplasty (ELCA) (n = 28, 22%) or additional stent implantation (n = 47, 36%).
PTCA was less frequently used in lesions with prior in-stent restenosis (14.8%, p < 0.05); ELCA was less frequently used in saphenous vein grafts (57.1%, p < 0.05). The procedural outcomes and restenosis rates were similar among groups. In the RA group, patients assigned or Ir192 had a larger minimal lumen diameter (1.6 +/- 0.5 vs 0.9 +/- 0.4 mm, p < 0.05) and lower diameter stenosis (39 +/- 7 vs 65 +/- 16%, p < 0.05) at follow-up angiography and a reduced late loss (0.2 +/- 0.5 v 0.9 +/- 0.5 mm, P < 0.05) and loss index (0 +/- 0.4 vs 0.8 +/- 0.4, p < 0.05) when compared to placebo. The incidence of delayed thrombosis was 7.7% in the ICB and 4.6% in the placebo group (p = 0.71); additional stenting, either alone (relative risk 12.36, 95% confidence interval 1.56 divided by 94.43) or followed by ICB (relative risk 3.80, 95% confidence interval 1.02 divided by 14.27), was correlated with an increased risk of late thrombosis.
ICB reduces the recurrence of in-stent restenosis through a reduction in late loss. In view of the higher risk of delayed thrombosis, additional stenting, either alone or followed by ICB, should be used with caution.
Italian heart journal: official journal of the Italian Federation of Cardiology 04/2002; 3(4):256-62.