Ivabradine improves coronary flow reserve in patients with stable coronary artery disease

OBJECTIVES

Although treatment with ivabradine reduces the incidence of hospital admissions for myocardial infarction and coronary revascularisation, there are no data concerning its effect on coronary circulation. The purpose of this study was to assess the effects of ivabradine on coronary flow velocity and flow reserve (CFR) in patients with stable coronary artery disease (CAD).

METHODS

During diagnostic coronary angiography (baseline), twenty-one patients with stable CAD underwent coronary flow velocity measurements (APV cm/s) in a non-culprit vessel, using a Doppler guidewire, at rest (r) and after adenosine administration to achieve maximal hyperaemia (h). During programmed coronary intervention in the culprit vessel, the same measurements were repeated one week after treatment with ivabradine (5 mg twice daily), both at the intrinsic heart rate and at a paced heart rate identical to that before treatment. CFR was defined as h-APV/r-APV.

RESULTS

Heart rate was significantly lower after treatment with ivabradine (78±14 bpm vs 65±9 bpm, p<0.001). Also, a reduction of r-APV (17.0±5.5 vs 19.7±7.6, p=0.003) and augmentation of h-APV (57.9±17.8 vs 53.5±21.4, p=0.009) leading to CFR improvement (3.51±0.81 vs 2.78±0.61, p<0.001) were observed. During pacing, although r-APV reverted to values similar to those before treatment (20.0±6.5 vs 19.7±7.6, p=NS), a sustained improvement in h-APV was observed (59.5±19.7 vs 53.5±21.4, p=0.007) and CFR remained higher than before treatment (3.04±0.66 vs 2.78±0.61, p<0.001).

CONCLUSIONS

Ivabradine treatment significantly improves hyperaemic coronary flow velocity and CFR in patients with stable CAD. These effects remain even after heart rate correction indicating improved microvascular function.

An international survey of physician and patient understanding, perception, and attitudes to atrial fibrillation and its contribution to cardiovascular disease morbidity and mortality

Aims

Atrial fibrillation (AF) is not always perceived as a serious health threat, but is the most common sustained arrhythmia, with a major impact on morbidity, mortality, and patient quality of life (QoL). A survey was undertaken to examine the level of understanding, perception, and attitudes of the cardiovascular risks associated with AF.

Methods and results

The AF AWARE group (an international coalition of organizations with an interest in AF) conducted an international quantitative survey in 11 countries in 2009, to investigate patients' (n = 825) and cardiologists' (n = 810) perceptions of AF, preferences for communicating information on AF and burden of AF. Both patients and physicians considered AF life-threatening (55 and 43%, respectively). Physicians were more concerned about the risk of stroke and hospitalizations than patients, whereas patients were most concerned about death risk. One in four patients felt unable to explain AF and >33% were worried or fearful about their disease. Many physicians (51%) wanted more patient information with >60% viewing available information as poor/difficult to find. Hospital specialists and GPs were identified as key information sources for patients. Most patients (83%) reported symptoms, yet 75% claimed to be satisfied with AF therapies. Atrial fibrillation patients, often with associated diseases, made an average of nine visits per year to their doctors, who consider AF difficult and time consuming to manage. Patients and physicians rated the QoL impact of AF as moderate to high.

Conclusions

A comprehensive international patient and professional information and support programme on AF is needed to improve management and consequently health outcomes.

Isolated left ventricular apical hypoplasia: a newly recognized unclassified cardiomyopathy

We describe two relatively asymptomatic cases diagnosed with the newly recognized unclassified cardiomyopathy, isolated left ventricular apical hypoplasia. The disease has been described mainly in cardiac magnetic resonance, whereas this study presents the echocardiographic characteristics of this new cardiomyopathy.

Myocardial gene expression alterations in peripheral blood mononuclear cells of patients with idiopathic dilated cardiomyopathy

AIMS

To assess cardiac gene expression in peripheral blood cells of patients with idiopathic dilated cardiomyopathy (IDCM) and its relationship to echocardiographic left ventricular (LV) function.

METHODS AND RESULTS

A complete echocardiographic study and blood sampling were performed in 65 consecutive stable IDCM patients with LV ejection fraction (LVEF) 31.76 +/- 10.07% and chronic mild to moderate heart failure (NYHA functional class II to III) for > or =9 months. Blood samples from 19 healthy individuals were included for comparison. Transcript levels of myocardin, GATA4, alpha- and beta-myosin heavy chain (MHC), sarcoplasmic reticulum calcium ATPase 2 (SERCA2), and phospholamban were determined by quantitative real-time reverse transcription-polymerase chain reaction. Myocardin (24.88 +/- 4.93 vs. 3.98 +/- 1.12, P = 0.0048) and GATA4 (17.85 +/- 4.85 vs. 0.45 +/- 0.15, P = 0.0069 x 10(-5)) were upregulated in IDCM patients compared with controls, whereas SERCA2 (5.11 +/- 0.42 vs. 8.93 +/- 1.07, P = 0.001) was downregulated. In IDCM patients, myocardin (r = 0.279, P = 0.025), GATA4 (r = 0.314, P = 0.011), beta-MHC (r = 0.444, P=0.0002), and alpha-MHC (r = 0.272, P = 0.034) showed positive correlations, whereas SERCA2 (r = -0.264, P = 0.034) exhibited a negative correlation with LVEF. Patients with elevated LV filling pressures had lower myocardin (15.06 +/- 3.10 vs. 43.12 +/- 12.03, P = 0.048), GATA4 (8.96 +/- 2.17 vs. 34.38 +/- 12.60, P = 0.026), beta-MHC (10.59 +/- 4.05 vs. 16.43 +/- 4.91, P = 0.013), and alpha-MHC (0.27 +/- 0.08 vs. 0.79 +/- 0.20, P = 0.033) and higher SERCA2 (5.65 +/- 0.54 vs. 3.90 +/- 0.61, P = 0.037) levels. Patients with atrial fibrillation (AF) had higher SERCA2 levels compared with sinus rhythm patients (6.75 +/- 0.84 vs. 4.54 +/- 0.45, P = 0.017).

CONCLUSION

Our data indicate that cardiac gene expression alterations in peripheral blood cells of IDCM patients may reflect alterations in LV function, whereas the presence of AF may be associated with increased SERCA2 levels in these patients.

Effect of sinus rhythm restoration after electrical cardioversion on apelin and brain natriuretic Peptide prohormone levels in patients with persistent atrial fibrillation

Because humoral alterations have been implicated in the generation and perpetuation of atrial fibrillation (AF), we aimed to elucidate possible abnormalities in atrial endocrine function in the setting of lone AF. Levels of plasma apelin and amino terminal fragment of the brain natriuretic peptide prohormone (NT-pro-BNP) were measured in 40 patients with persistent AF, before and 1 month after electrical cardioversion, and in 15 controls in sinus rhythm (SR). All patients were successfully cardioverted to SR, although in 9 of them AF recurred. Baseline apelin levels were lower and NT-pro-BNP levels higher in patients with AF compared to controls (380 +/- 186 vs 700 +/- 151 pg/ml, p <0.001, and 615 +/- 611 vs 50 +/- 28 pg/ml, p <0.001, respectively). Maintenance of SR resulted in an increase of apelin and a decrease of NT-pro-BNP levels during the postcardioversion follow-up period compared to baseline (497 +/- 170 vs 368 +/- 178 pg/ml, p <0.001, and 206 +/- 106 vs 398 +/- 269 pg/ml, p <0.001 respectively). Patients who developed AF recurrence by the end of the follow-up period had similar values of apelin and NT-pro-BNP on final and initial evaluations (444 +/- 142 vs 422 +/- 217 pg/ml, p = 0.62, and 1,328 +/- 714 vs 1,362 +/- 862 pg/ml, p = 0.74, respectively). Stepwise logistic regression analysis showed that left atrial diameter (b =-0.49, p = 0.05), and baseline NT-pro-BNP (b = 0.006, p = 0.022), but not apelin, were independent predictors for AF recurrence. In conclusion, this study suggests that endocrine heart function, as judged from apelin and NT-pro-BNP levels, is reversibly modified in the setting of lone AF. This could influence systemic hemodynamics and pharmacologic measures designed to treat this arrhythmia.

Biventricular pacing in paced patients with normal hearts

Right ventricular apical (RVA) stimulation, although beneficial in the treatment of symptomatic bradycardia, has proven detrimental in a substantial percentage of pacemaker recipients, leading to iatrogenic deterioration of left ventricular structure and function. Alternative right ventricular pacing sites appeared advantageous but their superiority has not been proven. Biventricular stimulation is effective in reducing ventricular dyssynchrony in subgroups of heart failure patients, improving their functional capacity, morbidity, and mortality. Therefore, it seems logical that this pacing strategy, by eliminating ventricular dyssynchrony, could play an important role in preventing the deleterious effects of chronic RVA stimulation in patients with normal hearts who undergo cardiac pacing for bradycardia indications. Preliminary investigations have yielded encouraging results, but further studies with harder endpoints such as quality of life, morbidity, and mortality are necessary to clarify the potentially advantageous effect of biventricular stimulation in paced patients with normal hearts.

Quadricuspid aortic valve associated with non-obstructive sub-aortic membrane: a case report and review of the literature

Quadricuspid aortic valve (QAV) is a rare congenital cardiac entity. The recognition of QAV has clinical significance because QAV causes aortic valve dysfunction, commonly aortic regurgitation. QAV is often associated with other congenital cardiac abnormalities. Our case represents, to the best of our knowledge, the first reported case of QAV with a non-obstructive sub-aortic membrane.

Prosthetic aortic valve endocarditis complicated with annular abscess, sub-aortic obstruction and valve dehiscence

We present a 76-year-old woman with infective endocarditis of a prosthetic aortic valve. The course of her illness started with an ischaemic stroke and she was admitted with prolonged fever and an episode of loss of consciousness. Echocardiography revealed acute aortic regurgitation and dehiscence of the prosthetic valve with excessive "rocking motion", aortic abscesses and left ventricular outflow obstruction caused by a semilunar shelf of tissue probably due to endocarditis vegetations. She underwent an urgent surgical procedure that confirmed the echocardiographic findings. Our case report reinforces the value of early diagnosis in the presence of a high clinical suspicion of prosthetic valve endocarditis. An extended workup, including transoesophageal echocardiography, in such a patient with a mechanical valve is mandatory.

Atrial fibrillation and heart failure in cardiology practice: reciprocal impact and combined management from the perspective of atrial fibrillation: results of the Euro Heart Survey on atrial fibrillation

OBJECTIVES

Our aim was to identify shortcomings in the management of patients with both atrial fibrillation (AF) and heart failure (HF).

BACKGROUND

AF and HF often coincide in cardiology practice, and they are known to worsen each other's prognosis, but little is known about the quality of care of this combination.

METHODS

In the observational Euro Heart Survey on AF, 5,333 AF patients were enrolled in 182 centers across 35 European Society of Cardiology member countries in 2003 and 2004. A follow-up survey was performed after 1 year.

RESULTS

At baseline, 1,816 patients (34%) had HF. Recommended therapy for HF with left ventricular systolic dysfunction (LVSD) with a beta-blocker and either an angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker was prescribed in 40% of HF patients, while 29% received the recommended drug therapy for both LVSD-HF and AF, consisting of the combination of a beta-blocker, either ACEI or angiotensin II receptor blocker, and oral anticoagulation. Rate control was insufficient with 40% of all HF patients with permanent AF having a heart rate < or =80 beats/min. In the total cohort, HF patients had a higher risk for mortality (9.5% vs. 3.3%; p < 0.001), (progression of) HF (24.8% vs. 5.0%; p < 0.001), and AF progression (35% vs. 19%; p < 0.001) during 1-year follow-up. Of all recommended drugs for AF and LVSD-HF, only ACEI prescription was associated with improved survival during 1-year follow-up (odds ratio: 0.51 [95% confidence interval: 0.31 to 0.85]; p = 0.011).

CONCLUSIONS

The prescription rate of guideline-recommended drug therapy for AF and LVSD-HF is low. Randomized controlled trials targeting this highly prevalent subgroup with AF and HF are warranted.

Appropriate management of syncope in a patient with hypertrophic cardiomyopathy: rationale behind long-term cardiac rhythm monitoring

We describe the case of a patient with hypertrophic cardiomyopathy who had recurrent syncopal episodes, the cause of which remained unexplained despite a thorough evaluation. Two years after his first evaluation, an implantable loop recorder revealed asymptomatic episodes of advanced second degree atrioventricular block while the patient was awake. Although a permanent pacemaker was implanted, the patient continued to suffer syncopal episodes, during which the pacemaker recorded episodes of ventricular tachycardia. Accordingly, the device was upgraded to an implantable cardioverter-defibrillator.