Relation Between Platelet Response to Exercise and Coronary Angiographic Findings in Patients With Effort Angina

Background— Platelet reactivity is increased by exercise in patients with obstructive coronary artery disease (CAD) but not in patients with syndrome X. In this study, we prospectively investigated whether the platelet response to exercise might help distinguish, among patients with angina, those with obstructive CAD from those with normal coronary arteries (NCAs). Methods and Results— Venous blood samples were collected before and 5 minutes after exercise from 194 consecutive patients with stable angina. Platelet reactivity was measured by the platelet function analyzer (PFA)-100 system as the time for flowing whole blood to occlude a collagen-adenosine diphosphate ring (closure time). Coronary angiography showed CAD in 163 patients (84%) and NCA in 31 patients (16%). Baseline closure time was shorter in NCA patients (78.0±16 versus 95.5±23 seconds, P <0.0001). With exercise, closure time decreased in CAD patients (−15.5 seconds; 95% confidence limits [CL], −13.0 to −18.0 seconds; P <0.0001), but increased in NCA patients (12.5 seconds; 95% CL, 7.4 to 17.7 seconds; P =0.0004). An increase in closure time with exercise ≥10 seconds had 100% specificity and positive predictive value for NCAs. Similarly, a decrease ≥10 seconds had 100% specificity and positive predictive value for CAD. A closure time change (increase or decrease) ≥10 seconds allowed a correct classification of 55% of all patients. Conclusions— Among patients with stable angina, the response of platelet reactivity to exercise was predictive of normal or stenosed coronary arteries at angiography. Specifically, an increase in closure time with exercise ≥10 seconds was invariably associated with the presence of NCA

Hypertension therapy and cardiovascular protection. Effects of angiotensin II receptor block with Valsartan

OBJECTIVES: Arterial hypertension and its pharmacological control are discussed in view of the high cardiovascular risk due to lack of target blood pressure achievement. It is, therefore, underlined the need for a highly effective therapy, able to provide protection from organ damage through a marked antihypertensive activity. In addition to this basic property, also compliance of the patient to therapy is needed, in order to avoid that the effects of therapeutic measures should result fruitless. DISCUSSION AND CONCLUSIONS: An answer to this problem appears now offered by a recent class of antihypertensive agents, the angiotensin II receptor blockers (ARBs). Among them valsartan has been described, providing an overview of methodologically adequate clinical studies, evaluating the efficacy, even at long-term, and safety. Valsartan has been compared with other antihypertensive agents of proven efficacy, mainly amlodipine, showing a better clinical profile. A wide room was finally left to the problem of adherence to therapy, whose lack is associated very frequently with marked increases in cardiovascular risk, due to absent or insufficient blood pressure control. This implies significant increases of health costs, as documented in numerous Countries, mainly following the higher need for hospitalization. On the other hand, it is also well documented the pharmacoeconomic benefit associated to ARBs use, particularly with valsartan

Atrial fibrillation and the pharmacological treatment: the role of propafenone

Atrial fibrillation is the most frequent cardiac rhythm disturbance, with prevalence increasing with age. This disease is a major risk factor for ischaemic stroke. The costs resulting from atrial fibrillation are really impressive. Pharmacological agents are the first line therapy for the management of atrial fibrillation. Antiarrhythmic drugs are used to terminate arrhythmias, as acute treatment for conversion of recent onset atrial fibrillation, and to maintain sinus rhythm, as chronic therapy for prevention of atrial fibrillation recurrences. Among antiarrhythmic agents, drugs that inhibit early sodium current (as propafenone) are proven effective in atrial fibrillation. In this review, the most relevant data on propafenone are provided

An Unusual Cause Of Bimodal Pattern Of Nocturnal Hypoxemia In An Obstructive Sleep Apnea Patient.

Background. Venous return and right atrial pressure are increased by clinostatism and by the intrathoracic negative pressure during obstructive sleep apneas. In presence of a interatrial defect this may results in right-to-left shunt. Case report. A 51-yrs obese male was admitted to the cardiology department of our hospital for evaluation of arrhythmias and exertional dyspnoea. He was also referred to the Respiratory unit because of dry mouth and sore throat upon awakening, daytime sleepiness and fatigue, snoring, restlessness during sleep, with a story of wheezing and recurrent bronchitis for years. He had a history of former smoking (20pack/yrs) and a prolonged occupational exposure to wheat. Lung function tests documented a mild chronic obstructive pulmonary disease and high values of the carbon monoxide transfer coefficient. Arterial blood gas analysis in ambient air and in spontaneous breathing was normal. A nocturnal cardiorespiratory polygraphy (CRP) documented a severe pattern of obstructive sleep apnoea syndrome (OSAS) (AHI=83/h, ODI=71/h), with hypoxemia (time with SpO2<90%=89%, <80%=53%). There were different fasis of severe prolonged hypoxemia with superimposed typical apnoeic desaturations (Fig.1). After a short awakening in standing position the hypoxemia recurred after about 1 hour of sleep. The deepest desaturations occurred in both right and left lateral positions. The number of hypo-apnoeic episodes was similar in both normoxemic and hypoxemic phases. The distribution of hypoxemia showed a bimodal pattern (Fig.2). A chest TC scan showed signs of COPD and air trapping during the expiratory phase, with no abnormal findings in the pulmonary circulation. A transthoracic ecocardiography documented a suspected interatrial right-to-left shunt with normal values of pulmonary artery systolic pressure (20 mmHg). A transesophageal ecocardiography confirmed the presence of an interatrial right-to-left shunt which occurred only during deep inspirations. After a 4 days progressive pressure titration, we prescribed the application of a continuous positive airway pressure (CPAP) of 13cmH2O with an oronasal mask during sleep. After 6 days a CRP with CPAP documented a marked improvement: AHI=9.3/h, ODI=8.1/h, time with SpO2<90%=7.6%, SpO2<80%=0%, with the usual unimodal pattern. A significant subjective improvement was reported. Conclusion. Our observation confirms the efficacy of CPAP therapy in reducing intermittent right-to-left shunt in interatrial defects in presence of OSAS. In our case sustained but inconstant hypoxemia was not explained by supine position or number of apnoeas and was temporarily reversed by a short standing period. Variable right-to-left shunt is a possible cause of a bimodal pattern of SpO2 distribution