Fresh leaves of the khat tree (Catha edulis Forsk.) are chewed for their euphoric properties in East Africa and parts of the Middle East, such as The Yemen. This review describes the history, cultivation and constituents of khat, and the social aspects of khat chewing in Yemen. The major pharmacologically active constituent of the fresh leaves is (--)-S-cathinone. The pharmacology of (--)-S-cathinone in the central nervous system and the peripheral effects are described. (--)-S-Cathinone is regarded as an amphetamine-like sympathomimetic amine and this mechanism of action is discussed in relation to the central stimulant actions and the cardiovascular effects of increasing blood pressure and heart rate. The risk factors associated with khat chewing are described, with emphasis on the reported increased incidence of acute myocardial infarction.

Patients with ACS in the Arab Middle East are younger than in developed countries and have higher rates of diabetes and smoking. There is good adherence to evidence-based medications; however, improvement in door-to-needle time and utilisation of interventional procedures is needed.

The leaves of khat (Catha edulis Forsk.) are chewed as a social habit for the central stimulant action of their cathinone content. This review summarizes the prevalence of the habit worldwide, the actions, uses, constituents and adverse health effects of khat chewing. There is growing concern about the health hazards of chronic khat chewing and this review concentrates on the adverse effects on health in the peripheral systems of the body, including the cardiovascular system and gastrointestinal tract. Comparisons are made with amphetamine and ecstasy in particular on the detrimental effects on the cardiovascular system. The underlying mechanisms of action of khat and its main constituent, cathinone, on the cardiovascular system are discussed. Links have been proposed between khat chewing and the incidence of myocardial infarction, dilated cardiomyopathy, vascular disease such as hypertension, cerebrovascular ischaemia and thromboembolism, diabetes, sexual dysfunction, duodenal ulcer and hepatitis. The evidence, however, is often based on limited numbers of case reports and only few prospective controlled studies have been undertaken. There is therefore an urgent need for more thorough case-control studies to be performed. This review outlines the current knowledge on the adverse health effects of khat chewing on the cardiovascular system and other internal medical problems, it assesses the evidence and the limitations of the studies and identifies the questions that future studies should address.

Aims The purpose of this study was to describe the clinical characteristics, management, and outcomes of acute heart failure (HF) patients from the Gulf acute heart failure registry (Gulf CARE). Methods and results Data from 5005 HF patients admitted to 47 hospitals in seven Gulf countries during February to November 2012 were analysed. Fifty‐five per cent of patients presented with acute decompensated chronic HF, while 45% had new‐onset HF. Mean age was 59 ± 15 years, 63% were males, and 83% were Gulf citizens. Co‐morbid conditions were hypertension (61%), diabetes mellitus (50%), CAD (47%), and atrial fibrillation or flutter (14%). The median LVEF was 35% (25–45%) with 69% presenting as HF with reduced EF (HFrEF). CAD was the most prevalent aetiology (53%) followed by idiopathic cardiomyopathy (18%), hypertensive heart disease (16%), and valvular heart disease (9%). At discharge, 71% and 78% of patients received beta‐blockers and ACE inhibitors/ARBs, respectively. Use of coronary intervention and device therapy was <10%. In‐hospital mortality was 6.3%. Re‐hospitalization and cumulative mortality at 3 and 12 months were 18%/13% and 40%/20%, respectively. Conclusions Gulf CARE results show that patients from this region are a decade younger than their Western counterparts, with a high prevalence of diabetes and HFrEF, and a lower prevalence of AF. Use of coronary intervention and device therapy was low, with high re‐hospitalization rates. Short‐ and long‐term mortality rates were similar to those of Western registries, but should be interpreted in the light of the younger age of Gulf CARE patients.

AimKhat chewing is a common habit in Yemen and east African countries. Millions of people chew khat leaves daily for its euphoric and energetic effects and to increase alertness. Cathinone, the main active substance in fresh khat leaves, has sympathomimetic effects which increase heart rate and blood pressure. The aim was to examine the hypothesis that khat chewing is a risk factor for acute myocardial infarction (AM I) using a hospital-based matched case-control study. MethodBetween 1997 and 1999, we selected 100 patients admitted to the Al-Thawra teaching hospital Sana'a ICU, Yemen with acute myocardial infarction. 100 control subjects, matched to cases for sex and age, were recruited from the outpatients clinics of the same hospital. A questionnaire was completed for case and control g roups covering personal history of khat chewing, smoking, hypertension, diabetes and any family history of myocardial infarction. A blood sample was collected for per forming lipid profiles. Cases and controls were compared by analysis conducted using conditional logistic regression which corrected for baseline imbalances leading to less biased estimations of odds ratio (OR). The risk associated with each classical factor and khat chewing habits was then investigated. OR values g reater than 2.5 indicated a significant risk factor. ResultsKhat chewing was significantly higher among the AMI case group than control group (OR = 5.0, 95% CI 1.9-13.1). A dose-response relationship was observed, the heavy khat chewers having a 39-fold increased risk of AMI. ConclusionThis study indicates that khat chewing is associated with AM I and is an independent dose-related risk factor for the development of myocardial infarction.