Case Study On A Patient With Heart Failure

Case Study On A Patient With Heart Failure Mr. SB, 60-year-old male is a retiree and was admitted to the hospital accompanied by his daughter. He is 100kg at a height of 180cm so his calculated body mass index (BMI) was 30.9 indicating that he was overweight. When admitted, patient was complained of shortness of breath for 2 weeks and was worsening on the day of admission. Besides, he also experienced orthopnea, fatigue, paroxysmal nocturnal dyspnea and leg swelling up to his thigh. Mr. SB was admitted to the hospital for to the same problem last year. Mr. SB had known case of heart failure since 3 years ago and he had also diagnosed with hypertension for 5 years. Before admitted to the hospital, patient was taking frusemide 40mg, aspirin 150mg, metoprolol 50mg, amlodipine 10mg, and simvastatin 40mg for his hypertension and heart failure. Patient does not allergic to any medication and he does not take any traditional medicines at home. His family history revealed that his father had died of ischemic heart disease 4 years ago while his brother has hypertension. As for his social history, he smokes 2-3 cigarettes a day for 35 years and the calculated smoking pack years was 5 pack years. Besides, Mr. SB also drinks occasionally. On examination, Mr. SB was found to be alert and conscious but he was having pedal oedema up to his knee. Besides, the patient was noted with bibasal crepitations with no rhonchi. His body temperature was normal. However, his blood pressure was found to be elevated upon admission with a record of 159/100 mmHg with an irregular pulse rate at 85beats/min. His echocardiogram showed that he had left ventricle hypertrophy while chest X-ray was conducted and revealed that the patient had cardiomegaly. Lab investigations such as full blood count, liver function test, urea and electrolyte test and cardiac enzyme were done upon admission. His creatinine concentration was found to be 143 µmol/L. Therefore, the calculated creatinine clearance was 68.8ml/min. Besides, there was also blood found in the urine and the echocardiography showed that the patient has sinus tachycardia. In addition, ECG test was performed on day 1 and the result indicated that there was a T-wave inversion. The patients INR was 1.04 which was lower than normal while APTT was found to be slightly higher (59.4 seconds). Mr. SBs random blood glucose was found to be normal during his hospitalization. Mr. SB was diagnosed with congestive cardiac failure (CCF) with fluid overload. The patient also suffered from hypertension. The management plan included intraveneous frusemide 40mg twice daily, aspirin 150mg once daily, simvastatin 40mg once at night and ramipril 2.5mg once a day. Besides, patient was asked to restrict his fluid intake to 500ml per day and oxygen therapy was given to patient at high flow using a face mask when patient experiencing shortness of breath. As for his clinical progression, on day 1, the patient was complained of shortness of breath, leg swelling and orthopnea. Enchocardiogram showed that he had cardiomegaly. Treatment of CCF was given. Throughout the stay in the hospital, Mr. SB had responded well to the heart failure therapy as there was no more complaint of chest pain or shortness of breath on day 13 and his pedal oedema had gradually improved. However, patients blood pressure throughout day 1 to 9 was fluctuating between the range of 102/67-160/100 mmHg and therefore, hypertension treatment was given and blood pressure on day 10 onwards had been seen fell within the normal range. Furthermore, Mr. SBs renal function became progressively worse from 143 µmol/L on admission to 175 µmol/L on day 11 and the calculated creatinine clearance on day 11 was 56.2ml/min. 2. Pharmacological Basis of Drug Therapy 2.1 Disease Summary Congestive cardiac failure (CCF) is a complex syndrome that is usually caused by the inability of heart to pump sufficient blood to meet metabolic needs of body during exercise. It is more commonly known as heart failure38 and it can affect either left or right ventricle or both39. The risk factors predisposing one to heart failure are obesity, high blood pressure, diabetes, and smoking. Heart failure is commonly characterized by typical signs of fluid retention with symptoms of breathlessness, fatigue, paroxysmal nocturnal dyspnoea, and reduced exercise tolerance39. CCF is a common disease which affects approximately 1-2% of the general population in developed countries1. Prevalence increases with age especially those aged above 75 years where the prevalence of CCF could be as high as 10%2. In addition, men are prone to getting heart failure as compared to women1. Each year, there are about 1-5 new cases of CCF per 1,000 population and it also increased with age40. In United Kingdom, the incidence of CCF is about 0.02 cases per 1000 per annum between the ages of 25-34. However, the incidence increased to 11.6 cases in those above 86 years old1. The prognosis for CHF is relatively poor. Approximately 40% of individuals with CCF die within a year after diagnosis3. There are many causes of CHF but the most common underlying causes are heart attack, coronary heart disease, and high blood pressure. Others such as cardiomyopathy, valvular heart disease and diabetes may also precipitate heart failure4. An early diagnosis of CHF is often based on the signs and symptoms which the patient is experiencing5. Other tests are needed to confirm or rule out the diagnosis. These include chest X-ray examination, physical examination, electrocardiograph (ECG), echocardiography and exercise testing. The severity of heart failure can be classified according to the New York Heart Association (NYHA) classification system. This system consists of four classes which relate patients symptoms to physical activities and quality of life. Table 1: New York Heart Association (NYHA) Classification5. Class Patient Symptoms I (Mild) No symptoms with ordinary physical activity (walking and climbing stairs) II (Mild) Slight limitation of activity with dyspnoea to severe exertions (climbing stairs or walking uphill) III (Moderate) Marked limitation of activity. Less than ordinary activity causes dypsnoea. (restricting walking distance and limiting climbing to one flight of stairs) IV (Severe) Severe disability, dyspnoea at rest. (unable to carry on physical activity without discomfort) 2.2 Drug pharmacology in treatment of congestive cardiac failure Chronic cardiac failure should be treated immediately once it is diagnosed. The goal of treatment is to improve patients quality of life by alleviating the symptoms, improving exercise tolerance, preventing the progression of myocardial damage as well as reducing hospital admission and mortality. Angiotensin-converting enzyme inhibitors (ACEis) ACE inhibitors are considered as first line therapy in patients with CCF5. They bind to and inhibit angiotensin converting enzyme which subsequently inhibit the action of angiotensin I. As a consequence, the production of angiotensin II is prevented. Angiotensin II is a potent vasoconstrictor which has a direct action on kidney to stimulate the secretion of aldosterone and antidiuretic hormone (ADH). This will cause sodium and water retention. Hence, ACE inhibitors improve cardiac function and relieve symptoms of oedema by promoting sodium and water excretion41. Besides, they also increase the concentration of a potent vasodilator, bradykinin. This results in a fall in blood pressure as bradykinin is associated with the release of nitric oxide and prostacyclin. However, high levels of bradykinin also responsible for the main adverse effect of ACE inhibitors, dry cough42. Other common side effects include hyperkalaemia, profound hypotension and gastrointestinal disturbances15. ACE inh ibitors are contraindicated in patients with renal impairment even though some studies have shown that they have renal protective properties43. Example of ACE inhibitors are captopril, enalapril, and ramipril. The starting dose for ACEis should be low and the dose should be increased gradually to target doses5. Beta blockers Beta blockers used to be contraindicated in patients with CCF as it may worsen the condition of the heart due to its negative inotropic effect. Nowadays, beta blockers should be considered in all patients with heart failure unless contraindicated5 as they have been shown to reduce the mortality, hospitalization and the progression of heart failure7. Beta blockers should be introduced following treatment with ACE inhibitor once the patients condition is stable7. Only bisoprolol, carvedilol, and nebivolol are currently licensed to be used in the treatment of heart failure in UK8. Both nebivolol and bisoprolol are cardioselective where they act on beta ­1 receptors. On the other hand, carvedilol is a non-selective beta blocker9, 10. The mode of action of beta blockers in heart failure is poorly understood but the proposed mechanisms include antiarrhythmic action, anti-ischaemic action, and attenuation of cathecholamine toxicity as well as reduced cardiac modelling through blockade of sympathetic influences on the heart9. Besides, carvedilol has an additional antioxidant property which may be thought to slow down the process of atherogenesis by inhibiting the oxygen-free radicals11, 12. The starting dose should be low as high doses may worsen the condition of heart failure7. Over time, the dose of beta blocker should be gradually titrated upward if the patient is well tolerated until target dose is reached5. Diuretics Diuretics are often used to relief the congestive symptoms and fluid retention7. Hence, they should be used in heart failure patients with the symptom of oedema7. Frusemide, a loop diuretic is the most commonly used agent in heart failure. It is considered as the first choice of drug for the long-term treatment of CCF with the advantages of improves cardiac function, exercise tolerance, as well as symptoms of breathlessness and oedema13. The main site of action is at the thick ascending limb of the loop of Henle. Furosemide acts at the Cl- binding site of Na+/K+/2Cl- co-transport and as a result, sodium reabsorption is inhibited. This promotes the excretion of sodium up to 20-25% as well as enhances water clearance13. Consequently, it reduces the blood volume thus reducing the preload on the heart. As a result, ventricular ejection is improved and the heart is able to pump more efficiently14. The most common side effect is hypokalaemia. Hence, it is important that patients potassium level and the renal function are closely monitored. Aldosterone Antagonists Patients with moderate to severe heart failure should be considered for the treatment of aldosterone antagonists such as spironolactone15. It is a potassium sparing diuretic where its action is mainly on the renin-angiotensin-aldosterone (RAA) system18. Spironolactone prevents the synthesis of basolateral Na+/K+-ATPase pump protein by acting as a competitive inhibitor at the aldosterone receptor site in the distal convoluted tubules. As mentioned earlier, aldosterone promotes sodium and water retention and the use of spironolactone therefore inhibits sodium and water reabsorption while retains potassium. As a result, spironolactone reduces the workload of the heart and the heart is therefore able to work more efficiently18. It is often use in conjunction with other agents such as diuretic in the management of CCF44. Nevertheless, spironolactone may cause hyperkalaemia, particularly in patients with renal impairment due to the inhibition of potassium excretion. Hence, the patients pot assium level and the renal function should be closely monitored. 3. Evidence for treatment of the condition(s) Angiotensin-Converting Enzyme Inhibitors (ACEis) ACE inhibitor, ramipril prescribed for my patient Mr. SB was proven to be the mainstay therapy in the management of CCF. NICE and SIGN guidelines recommended that ACE inhibitor therapy should be started once the patient is diagnosed with CCF before beta blocker is initiated5, 32. It should be prescribed to the patients with heart failure due to left ventricular dysfunction as studies have demonstrated that ACE inhibitors alleviate symptoms and reduce rehospitalisation as well as slow down the progression of the disease in all NYHA classes5, 33. The benefits of ACE inhibitor in CCF can be seen based on the systemic review of 5 randomised, controlled trials which involve a total of 12763 patients. Results shown that in comparison to placebo group, long term treatment with ACE inhibitors were shown to have statistically significant reduction in mortality rate (23.0% vs 26.8%; p