Aortic atherosclerotic lesions in the thoracic aorta detected by multiplane transesophageal echocardiography as a predictor of coronary artery disease in elderly patients

BACKGROUND

The presence of atherosclerotic lesions in the thoracic aorta by transesophageal echocardiography (TEE) appears to be a marker for the presence of significant coronary artery disease (CAD) in the general population.

HYPOTHESIS

We investigated whether atherosclerotic lesions in the thoracic aorta, by multiplane TEE, could be a marker for CAD in elderly patients.

METHODS

In all, 127 patients (67 men, 60 women, aged 68 +/- 13 years), underwent a TEE study with imaging of the thoracic aorta and cardiac catheterization with coronary angiography. The presence of a distinct, linear, or focal, highly echogenic mass protruding into the vessel lumen was the criterion for the diagnosis of atherosclerotic plaque.

RESULTS

Atherosclerotic lesions were found in 30 of 36 patients (83.3%) with and in 20 of 91 (22%) without CAD. Of the 41 patients > or = 70 years, atherosclerotic lesions were detected in 14 of 17 (82.3%) with and in 13 of 24 patients (54%) without CAD. The sensitivity, specificity, and positive and negative predictive values in this group were 82.3, 46, 52, and 78.6%, respectively. Multivariate logistic regression analysis revealed that in patients aged > or = 70 years only advanced atherosclerotic lesions were independent predictors of significant CAD. However, the high negative predictive value of the method indicates that the absence of aortic plaque is a strong predictor of the absence of CAD.

CONCLUSIONS

The presence of atherosclerotic lesions in the thoracic aorta is a strong predictor of CAD only in patients < 70 years old. However, the negative predictive value of the method is high for all patients regardless of age.

Extracellular matrix alterations in patients with paroxysmal and persistent atrial fibrillation: biochemical assessment of collagen type-I turnover

OBJECTIVES

We investigated whether the serum markers of collagen turnover differed in various forms of atrial fibrillation (AF) and in sinus rhythm (SR) in humans.

BACKGROUND

Structural alterations and fibrosis have been implicated in the generation and perpetuation of AF.

METHODS

Serum C-terminal propeptide of collagen type-I (CICP), C-terminal telopeptide of collagen type-I (CITP), matrix metalloproteinase-1, and tissue inhibitor of matrix metalloproteinases-1 were measured as markers of collagen synthesis and degradation in 70 patients with AF and 20 healthy control subjects in SR.

RESULTS

C-terminal propeptide of collagen type-I and CITP were significantly higher in AF patients than in control subjects (91 +/- 27 ng/ml vs. 67 +/- 11 ng/ml, p < 0.001 and 0.38 +/- 0.20 ng/ml vs. 0.25 +/- 0.08 ng/ml, p < 0.001, respectively). Persistent AF patients had higher levels of CICP (105 +/- 28 ng/ml vs. 80 +/- 21 ng/ml, p < 0.001), but not CITP, compared with those with paroxysmal AF. Patients with persistent AF had lower levels of matrix metalloproteinase-1 but increased levels of tissue inhibitor of matrix metalloproteinases-1 compared with patients with paroxysmal AF (11.90 +/- 4.79 ng/ml vs. 14.98 +/- 6.28 ng/ml, p = 0.03 and 155 +/- 45 ng/ml vs. 130 +/- 38 ng/ml, p < 0.001, respectively). Tissue inhibitor of matrix metalloproteinases-1 levels were significantly lower in control subjects compared with those in both paroxysmal and persistent AF patients (102 +/- 15 ng/ml vs. 130 +/- 38 ng/ml vs. 155 +/- 45 ng/ml, respectively, p < 0.001).

CONCLUSIONS

Serum markers of collagen type-I turnover differed significantly between patients with AF and SR. Furthermore, these markers also differed significantly between paroxysmal and persistent AF patients, suggesting that the intensity of the extracellular synthesis and degradation of collagen type-I may be related to the burden or type of AF.

Tools and strategies for the reduction of inappropriate implantable cardioverter defibrillator shocks

Implantable cardioverter defibrillators (ICDs) have been shown to provide a survival benefit in patients at high risk of sudden cardiac death. A major problem associated with ICD therapy is the occurrence of inappropriate shocks which impair patients' quality of life and may also be arrhythmogenic. Despite recent technological advances, the incidence of inappropriate shocks remains high, thus posing a challenge that we have to meet. In the present review we summarise the available tools and the strategies that can be followed in order to reduce inappropriate ICD shocks.

Sleep-disordered breathing in heart failure and the effect of cardiac resynchronization therapy

Respiratory disturbances during sleep are common in patients with heart failure (HF) and can trigger the occurrence of sleep apnoea or deteriorate pre-existing breathing disorder. This in turn may lead to worsening of the HF itself. Optimal treatment for HF has been found to reduce respiratory disturbances during sleep significantly, whereas cardiac resynchronization therapy (CRT), achieved by biventricular pacing, appears to cause a further reduction in episodes of central type apnoea, although it may also have an effect on episodes of obstructive type. The beneficial effect of CRT is due to the patients' haemodynamic improvement and in the HF amelioration, and not due to some other effect resulting from the electrical stimulation of the heart. However, this therapeutic intervention by itself is insufficient for the effective treatment of respiratory disturbances during sleep and should be considered as an adjunctive treatment in addition to other established therapies.

Isolated atrial microvascular dysfunction in patients with lone recurrent atrial fibrillation

OBJECTIVES

The purpose of this study was to assess atrial myocardial perfusion in patients with lone recurrent atrial fibrillation (LRAF).

BACKGROUND

Although acute atrial ischemia has been implicated in the pathogenesis of atrial fibrillation, there are few data concerning human atrial myocardial perfusion and none for patients with LRAF.

METHODS

Sixteen patients with LRAF and 15 control subjects with suitable coronary anatomy underwent time-averaged peak coronary blood flow velocity (APV) measurements (cm/s), using a Doppler guidewire in the proximal left circumflex coronary artery (LCx) and in the left atrial circumflex branch (LACB), at baseline (b) and after adenosine administration to achieve maximal hyperemia (h). Coronary flow reserve was defined as h-APV/b-APV.

RESULTS

Although there were no statistically significant differences in b-APV between patients with LRAF and control subjects or between the LACB and LCx, there were significant group (p = 0.002), artery (p = 0.001), and interaction (p < 0.001) effects at maximal hyperemia. In patients with LRAF, the h-APV and coronary flow reserve of the LACB (30.4 +/- 9.5 cm/s and 2.2 +/- 0.4, respectively) were significantly lower than in the LACB of the control subjects (45.8 +/- 12.8 cm/s [p < 0.001] and 2.9 +/- 0.5 [p = 0.001], respectively) or in the patients' LCx (43.0 +/- 10.9 cm/s [p = 0.001] and 3.1 +/- 0.6 [p < 0.001], respectively).

CONCLUSIONS

This study confirms for the first time isolated atrial myocardial perfusion abnormalities in patients with LRAF and coronary flow reserve impairment, indicating that microvascular dysfunction is a pathophysiological substrate associated with this arrhythmia.

Prognosis, disease progression, and treatment of atrial fibrillation patients during 1 year: follow-up of the Euro Heart Survey on atrial fibrillation

AIMS

To gain insight in the prognosis and treatment of atrial fibrillation (AF) patients during 1-year follow-up in the Euro Heart Survey (EHS) on AF.

METHODS AND RESULTS

The EHS enrolled 5333 AF patients in 2003--2004. One-year follow-up data were available for 80%. Of first detected AF patients, 46% did not have a recurrence during 1 year, paroxysmal AF largely remained paroxysmal AF (80%), and 30% of persistent AF progressed to permanent AF. Many treatment changes occurred since baseline. Oral anticoagulation was started in 19% and discontinued in 16% of all patients. Of patients initially on rhythm control 27% did not receive rhythm control during follow-up, whereas 15% of patients initially on rate control received rhythm control. Mortality was highest in permanent AF (8.2%), but also substantial in first detected AF (5.7%). In multivariable analysis, sinus rhythm at baseline was associated with lower mortality, but no significant effect was observed regarding the application of either rhythm or rate control.

CONCLUSION

The EHS on AF provides unique prospective observational data on AF progression, long-term treatment, prognosis, and determinants of adverse outcome of the total clinical spectrum of AF in a European cardiology-based patient cohort.

The role of the post-cardioversion time course of hs-CRP levels in clarifying the relationship between inflammation and persistence of atrial fibrillation

OBJECTIVES

Although recent studies suggest that inflammation is involved in the pathogenesis of atrial fibrillation (AF), it remains controversial whether it is a consequence or a cause of the arrhythmia.

DESIGN

Prospective study.

SETTING

Tertiary referral centre.

PATIENTS AND INTERVENTIONS

In 52 patients with persistent AF lasting >3 months, high-sensitivity C-reactive protein (hs-CRP) was measured before and after electrical cardioversion.

MEASUREMENTS AND RESULTS

All patients were successfully cardioverted to sinus rhythm (SR), but the recurrence rate was 23% at 1 month. Baseline hs-CRP was higher in patients with AF recurrence than in those who remained in SR (0.5 (SD 0.18) mg/dl vs 0.29 (SD 0.13) mg/dl, respectively, p<0.001). Similarly, arrhythmia recurrence was associated with greater left atrial diameters (45.4 (SD 3.3) mm vs 40.7 (SD 3.1) mm, respectively, p<0.001). However, logistic regression analysis showed that hs-CRP was the only independent predictor for AF recurrence (p<0.001). Additionally, patients who were in SR on final evaluation had significantly lower hs-CRP levels than at baseline (0.10 (SD 0.06) mg/dl vs 0.29 (SD 0.13) mg/dl, respectively, p<0.001), while those who experienced AF recurrence had similar values on final and on initial evaluation (0.56 (SD 0.24) mg/dl vs 0.50 (SD 0.18) mg/dl, respectively, p = 0.42).

CONCLUSION

High levels of hs-CRP are associated with an increased risk of AF recurrence after cardioversion. The restoration and maintenance of SR result in a gradual decrease of hs-CRP while AF recurrence has a different effect, suggesting that inflammation is a consequence, rather than a cause, of AF.

Electrophysiological effects of carvedilol administration in patients with dilated cardiomyopathy

PURPOSE

Several studies suggest the clinical efficacy of carvedilol in reducing atrial and ventricular arrhythmias in patients with left ventricular dysfunction (LVD) due to congestive heart failure (CHF) or following myocardial infarction. However, the mechanisms supporting its antiarrhythmic efficacy have been derived from experimental studies. In this prospective, placebo-controlled trial we examined the electrophysiological effects of a high oral dose of carvedilol in patients with CHF and LVD due to non-ischemic dilated cardiomyopathy.

METHODS

Thirty-one patients with stable CHF underwent electrophysiological study and were randomly assigned to treatment with carvedilol or placebo. After 2 months of treatment the study was repeated.

RESULTS

Carvedilol prolonged almost all conduction times. In the same group atrial and ventricular effective refractory periods were significantly prolonged, while the parameters of repolarization remained virtually unchanged. The prolongation of refractoriness was most pronounced in the atrium. The change in ventricular refractoriness was correlated with ejection fraction (r = 0.94, p < 0.01) suggesting that patients with more preserved left ventricular function responded to treatment with greater prolongation.

CONCLUSION

Even after a short period of administration carvedilol has marked and diffused electrophysiological effects that would be beneficial for patients with CHF and may contribute to the positive outcome of clinical trials.

Risk factors for ischaemic heart disease in a Cretan rural population: a twelve year follow-up study

BACKGROUND

Crete has been of great epidemiological interest ever since the publication of the Seven Countries Study. In 1988 a well-defined area of rural Crete was studied, with only scarce signs of coronary heart disease (CHD) despite the unfavorable risk profile. The same population was re-examined twelve years later aiming to describe the trends of CHD risk factors over time and discuss some key points on the natural course of coronary heart disease in a rural population of Crete.

METHODS AND RESULTS

We re-examined 200 subjects (80.7% of those still living in the area, 62.4 +/- 17.0 years old). The prevalence of risk factors for CHD was high with 65.9% of men and 65.1% of women being hypertensive, 14.3% of men and 16.5% of women being diabetic, 44% of men being active smokers and more than 40% of both sexes having hyperlipidaemia. Accordingly, 77.5% of the population had a calculated Framingham Risk Score (FRS) > or = 15%, significantly higher compared to baseline (p < 0.001). The overall occurrence rate for CHD events was calculated at 7.1 per 1000 person-years (95% confidence interval: 6.8-7.3).

CONCLUSION

The study confirms the unfavorable risk factor profile of a well defined rural population in Crete. Its actual effect on the observed incidence of coronary events in Cretans remains yet to be defined.