Primary Care Pharmacy March 2000 Vol 1 No 2 p55-57

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Angina management - are patients adequately controlled?

By Sheena Macgregor, MSc MRPharmS

Switching patients from a slow-release to a conventional release preparation of isosorbide mononitrate, as part of a patient review programme, saved money and improved quality of care

A significant proportion of the population suffer from angina, which is characterised by a constricting chest pain experienced when coronary blood supply is insufficient to meet the oxygen demands of cardiac muscle. There are a number of other causes of chest pain, including localised musculoskeletal pain, oesophageal spasm, pleuritic pain and pain linked to hyperventilation. Ischaemic pain can be defined by asking the following questions:

Where is the pain?
Where does it go?
What does it feel like?
What brings it on?
What relieves it?

In recent years, national guidelines have ensured that more patients with angina are being appropriately diagnosed and managed according to a stepwise approach (Figure 1). Guidelines are largely concerned with strategies for the management of patients presenting for the first time. However, in chronic conditions, such as angina, review of established patients may be a higher priority. My experience in one practice led me to realise that, while management of new patients and those presenting with worsening symptoms was well established, the quality of care provided for existing patients receiving repeat medication for many years was less well known. These patients appeared to be reviewed infrequently and were not always receiving current evidence-based care.

Figure 1 Stepwise approach to drug treatment of angina
Stage 1:	Patients who suffer infrequent chest pain in response to precipitating factors.
Treatment:	Sublingual or buccal GTN and low dose aspirin
Stage 2:	Patients requiring GTN more frequently and symptoms and/or daily activities affected.
Treatment:	Add beta-blocker If contraindicated verapamil is the preferred alternative If neither is tolerated, any alternative preparation may be tried
Stage 3:	Patients not adequately controlled on one drug.
Treatment:	If taking a beta-blocker add a dihydropyridine (NOT verapamil or diltiazem) If taking a beta-blocker and intolerant of dihydropyridines add isosorbide mononitrate If taking verapamil or a dihydropyridine, add isosorbide mononitrate If taking a nitrate, add any calcium channel blocker
Stage 4:	Patients not adequately controlled on two drugs.
Treatment:	If inadequately controlled on maximum therapeutic doses of two drugs, patients should be referred to a cardiologist rather than prescribed a third drug. If a third drug is added while waiting for an appointment, its effects should be monitored and it should be stopped if ineffective.
(Based on the North of England Guidelines, BMJ 1996;312:827)

Can a pharmacist help?

The multidisciplinary team based at the surgery decided to build on previous experience with pharmacist-led disease management clinics to review existing angina patients. Patients were identified using a computerised drug search for BNF chapters 2.4 and 2.6 (beta-blockers, nitrates, calcium channel blockers, potassium channel activators). I reviewed the medical notes of these patients and completed an audit form (Figure 2). Patients were then invited to attend a pharmacist clinic for medication review. Where care issues were identified from the review of case notes, discussion with the patients' doctor was carried out in advance of the patient's appointment with the pharmacist. This allowed changes to be made while the patient was present, rather than having to contact them again later, or arrange follow up appointments.

Figure 2 Audit form

Name:
Address:
Date of birth:
Occupation:
Investigation
Smoker Y/N
If yes, have they been advised to stop? Y/N
Offered support via surgery clinic? Y/N
Is anything known to precipitate an attack?
If so action taken.
Is regular exercise undertaken? Y/N (At least 3 x 30mins aerobic per week)
Weight
Body mass index
Weight loss encouraged? Y/N
Random blood glucose measured? Y/N
If >10mmol/L what action taken?
Serum cholesterol measured? Y/N
If >5.4mmol/L what action taken?
Blood pressure monitored?
If diastolic >90mmHg or systolic > 160mmHg what action taken?
Haemoglobin measured? Y/N
Evidence of left ventricular failure?
ACE inhibitor prescribed if present?
ECG carried out? Y/N
Referred for exercise testing? Y/N
Drug treatment
Current therapy:
Hospital referral
Referred to where?
And for what?
Care plan supplied on hospital discharge? Y/N

What did I find?

Many elderly patients had not had their angina therapy reviewed for many years and appeared to accept increased frequency of pain as part of the ageing process. Often they had been prescribed nitrates without a drug to slow heart rate and reduce cardiac work.
Patients were not taking low-dose aspirin, a highly cost-effective, evidence-based treatment. If aspirin was not prescribed on the repeat prescription, 75mg was started, unless contraindications prevented its use.
Previously unaddressed coronary heart disease risk factors were identified.
A few patients had no proven diagnosis and were unsure why they were taking medication.
As part of the review process, 64 per cent of patients were changed from slow-release (SR) nitrates to asymmetric bd dosing of conventional isosorbide mononitrate. These patients were supplied with a glyceryl trinitrate (GTN) diary, asked to record their GTN usage over four weeks and were to contact the surgery if usage increased or if any worsening of chest pain occurred. Only three patients (0.1 per cent), reported increased chest pain and were restarted on a long-acting preparation.
Eighty one per cent of patients had a medication issue unrelated to their angina treatment, which was subsequently resolved.
Patients were counselled with regard to any changes made to their medication using leaflets to reinforce information given verbally, and the repeat prescribing record was updated. Appropriate lifestyle advice was given and patients were referred to the appropriate surgery clinic where other risk factors required attention (Figure 3).

Fig 3 Angina management in existing patients

Did the "care pathway" work?

This approach to patient management is based on an adaptation of the pharmacist-led clinic approach, to co-ordinate management of new and existing patients with chronic stable angina. Multidisciplinary care pathways are being developed more commonly within secondary care services, but are not often a feature in primary care.
Where general practitioners, nurses and professions allied to medicine (PAMs) provide care packages, medication-related issues are often unidentified or their importance overlooked. In cardiovascular disease, patients are commenced on new medicines for long-term treatment. Many of these medicines have significant side effects, particularly in the initial weeks. Drugs are often prescribed without providing patients with appropriate information, which is an important component to not achieving concordance.
A pharmacist can provide the skills necessary to facilitate protocol development, audit of care pathways, promote lifestyle changes and medication compliance and direct patients to the most appropriate team member to address any risk factors identified. Through establishing a review clinic for patients already receiving medication for angina, other pharmaceutical care issues can be identified and dealt with, and appropriate monitoring can be carried out.
The care pathway promotes collaboration and communication among members of the health care team and reduces unnecessary variation in management of the patients. It also ensures that all patients receive consistent, high quality care by the most appropriate team member. There is greater understanding of each other's role within the team and of the care package being provided for the patient as a whole. A review clinic focuses the team on the needs of the patient, minimising territorial issues between members and allowing them to concentrate on improving continuity of care. A pharmacist proved to be an appropriate team member to take responsibility for co-ordination of the pathway.
The significant cost difference between once daily SR isosorbide mononitrate and asymmetric bd dosing financed this exercise. By reviewing patients within a clinic setting, other related and unrelated care issues could be identified and addressed. Patients appreciated the opportunity to discuss their medicines and lifestyle advice could be reinforced as necessary.
Having identified that there was a cohort of patients with angina who had risk factors that had not been addressed, the team decided to create a database of patients with cardiovascular disease and to review them systematically for risk factors. The result two years on is that few patients who attend the practice-based clinics have more than two risk factors.