Haitham Amin¹, Kadhim Sulaiman², Fuad Abdulkader³, Ibrahim Al Rashdan³, Jassim Al Suwaidi³, Mohammed Arafah³, Wael Al Mahmeed³

Introduction:

The Arabian Gulf Countries, like many other developing countries, have witnessed a rapid development in many aspects of life during the last few decades. Epidemiological transition has already occurred; a sharp decline in infectious and nutritional deficiency diseases and a gradual increase in chronic diseases have occurred in these countries. The prevalence of cardiovascular risk factors has increased, The prevalence of diabetes mellitus is the highest worldwide approaching 15-25% of the adult population. More than 70% of the adult population have excess body weight (overweight or obese). Twenty six percent of the adult population are hypertensive, 54% have hypercholesterolemia and 13-40% are smokers.

In the last decade of the 20th century, cardiovascular diseases, primarily coronary atherosclerosis and heart failure, have become the leading causes of morbidity and mortality in the Gulf countries. According to Gulf RACE, the mean age of native patients with acute coronary syndrome in the Gulf was 62 years for women and 59 years for men. Diabetes Mellitus was the commonest risk factor, present in over 50% of patients, which is double the rate reported in other communities. Furthermore diabetes was more common in women than men (68.5% compared to 48%). Hypertension was present in 43%, hypercholesterolemia in 30% and smoking in 25% of patients. Acute coronary syndrome without persistent ST-segment elevation accounted for 50% of cases. Although there has been an increase in the use of appropriate therapeutic modalities in patients with acute coronary syndromes in our communities, their use remains sub-optimal, calling for the need to develop evidence-based guidelines that can help in optimizing the care of our patients.

The GHA assigned a working group to develop an up-to-date guideline for the treatment of acute coronary syndrome, adopted from the latest update of both ESC and ACC/AHA guidelines.

Diagnosis, Evaluation and Management:

Initial Assessment and Evaluation

The initial assessment includes the following four steps [Figure 1].

1. A targeted history and physical examination with special attention to valvular heart disease (especially Aortic Stenosis), hypertrophic cardiomyopathy, heart failure, pulmonary hypertension and Aortic dissection
2. A stat ECG (with comparison to an older one, if available). Once performed, patients suspected of having ACS are divided into two categories:
   1. STEMI or new LBBB.
   2. NON-STEMI ( ST-segment depression, T-wave changes, Normal ECG and, Indeterminate changes Pacemaker Rhythm, old LBBB).
3. Blood tests should include BiochemicalMarkers and enzymes of myocardial necrosis {Cardiac Troponin I (TnI) and / or T (TnT); CK-MB}. Serial sets (at 0hr-6hr-12hr) should be obtained.
4. If a new episode of chest pain lasting longer than 10 minutes occurs, a repeat 12-lead ECG should be obtained. Echo-cardiographic evaluation of left ventricular function is helpful to assess regional wall motion abnormality.

Patients with NON-STEMI can then be sub-classified as having :

1. Myocardial infarction (Non-STEMI), with elevated biochemical markers.
2. Unstable Angina (normal biochemical markers)
3. Non-Cardiac Chest Pain (Normal ECG, Normal Biochemical Markers, Atypical chest pain).

The initial management should include:

1. ABCs
2. M.O.N.A. (Morphine; Oxygen; SL Nitroglycerin; Aspirin) Aspirin dose 150-300mg chewed or swallowed, followed by 75-150mg daily.
3. Clopidogrel {Loading dose 300mg (600mg if intervention is planned), followed by 75mg daily}.
4. LWMH (Enoxaparin) or un-fractionated heparin or fondaparinux.
5. Antianginal Agents: Beta-Blockers, Nitrates, ΁ Calcium Antagonists. The latter may be preferred over beta-blockers in those with bronchospasm or intolerance to the drug.

In the subsequent observational period (8-12 hours), specific attention should be given to recurrence of chest pain during which an ECG should be recorded. Signs of hemodynamic instability should be carefully noted (hypotension, pulmonary crackles) and treated. Within this initial period, risk assessment can be performed based on the clinical, electro- cardiographic and biochemical data, and a further treatment strategy selected.[Additional file 1]

Invasive strategy

– Cardiac catheterization is advised to prevent early complications and/or to improve long-term outcome. Accordingly, the need for and timing of an invasive strategy has to tailored according to the acuteness level of risk the three risk categories are:

– Conservative

– Early invasive

– Urgent invasive

Patients who fulfill all the below criteria may be regarded as low risk and should not be submitted to early invasive evaluation.

• No recurrence of chest pain.
• No signs of heart failure.ECG
• No abnormalities in the initial and second ECG (6-12h).
• No elevation of troponins (arrival and at 6-12h).

Low risk as assessed by a risk score [Figure 2] can support the decision-making process for a conservative strategy. The further management in these patients is according to the that of stable CAD.

Before discharge, a stress test for inducible ischemia is useful for further decision-making. Patients who cannot be excluded by the above criteria should go on to CT-Angiography or cardiac catheterization.[Additional file 2]

Long-term management

5.1. Aggressive risk factor modification is warranted in all patients following diagnosis of ACS. It is mandatory that patients stop smoking. Referral to smoking cessation clinic I recommended.

5.2. Blood pressure control should be targeted goal is < 135/85 mmHg.

5.3. Diabetes: Glycemic control ( targeted goal HbA1c <7%).

5.4. Life long Aspirin (75-150mg) and at least 9-12 months Clopidogrel (75mg/day) should be prescribed. Clopidogrel should replace aspirin in patients with hypersensitivity or major gastro-intestinal intolerance to aspirin.

5.5. Beta-blockers improve prognosis in patient after myocardial infarction and should be continued after acute coronary syndromes.

5.6. Lipid lowering therapy should be initiated without delay and optimized to targeted goal of < 1.8 mmol/L particularly HMGCoA reductase inhibitors (statins).

5.7. ACE-inhibitors in secondary prevention of acute coronary syndromes should be considered in all patients especially those at high risk. ACE inhibitors are indicated long-term in all patients with LVEF 40% and in patients with diabetes, hypertension, or CKD, unless contraindicated. Since coronary atherosclerosis and its complications are multifactorial, much attention should be paid to treat all modifiable risk factors in an effort to reduce recurrence of cardiac events.

5.8. Gradual resumption of exercise recommended with 30 minutes of brisk walking.^[4][Figure 1],[Figure 2],[Figure 3]