What is angina and how is it treated?
What is angina
This is a form of coronary heart disease, and has numerous forms. These are stable angina (occurs in response to stress such as exercise), silent ischaemia (same as angina whereby there is a reduction in oxygenated blood flow to the heart is reduced, but there are no symptoms such as chest pain), syndrome X (again angina, but the coronary arteries are healthy), Prinzmetals angina (where there is vasospasm-arteries constricting, in cycles) and Acute Coronary Syndromes (ACS- unstable angina, ST Segment Elevated MI, and non ST elevated MI). There are numerous risk factors for angina. Modifiable factors are hypertension, diabetes, hypercholesterolaemia and smoking. Non-modifiable factors are age, sex and family history.
With regards to the incidence rates, the UK as a whole has the worst incidence of angina. In males, the highest incidence occurs in NI and Scotland, and in females, the highest incidence is seen in England/Wales and Scotland.
Treatment options for those with angina
The aims of the therapy is to prevent the progression of the disease, and also control the symptoms. To prevent its progression, antiplatelets, statins, beta blockers and ACEI’s can be given. To control the symptoms, beta blockers, calcium antagonists (reduces muscular contraction), nitrates (both short and long acting, dilate arteries and veins), potassium channel openers, If channel inhibitors and slow sodium channel blockers. The antiplatelets used are aspirin in all patients unless contraindicated, such as there being an allergy or GI bleeding. Clopidogrel may be used if the patient is intolerant to aspirin (although a PPI should be used first), they are sensitive to aspirin, they have previous ACS or previous PCI. It is usually given as 75mg a day (although sometimes given as 150mg). it should also be monitored for side effects, such as GI bleeding.
It will probably be given for life, although the duration of Clopidogrel will depend on the reason. Statins are given in all patients unless they are contraindicated (such as in active liver disease). There are different dosing strategies available. When the target TC is less than 5mmol/l or LDL less than 3 mmol/l, a suitable dose to effect will be given. In aggressive TC reduction, even if its below 5 mmol/lm Simvastatin will be given daily at 40mg. in the case of ACS, a very aggressive TC reduction regime will be employed, such as using Atorvastatin at 80mg day. The stains will be monitored for effectives by measuring the lipid profile. Toxicity will also be monitored, which is indicated by symptoms of myopathy, markers of myopathy-creatine kinase, if there are symptoms present as well as measurement of liver function (AST/ALT). these will be measured at baseline and also during treatment, especially so if there is a high dose of statins given. Again, it is likely that the patient will be on these for life.
There is no evidence that beta-blockers have a benefit in stable CHD. However, they do exhibit a protective and symptom controlling effect. They will be given in all patients unless contra-indicated. This would be in patients with asthma, severe peripheral vascular disease, heart block/bradycardia and also hypotension since they work by lowering blood pressure. There is no specific dose given, and therefore dependent on each patient. When using these, sudden withdrawal should be prevented if possible since it can cause hypertension. In the case of toxicity, it will present as cold extremities, nightmares, fatigue (especially when started), wheeze and also impotence. However, these are uncommon.