Heart Failure Interventions
Heart failure is a condition where the heart muscle slowly weakens (Systolic dysfunction) and results in poor pumping of the blood from the heart to all parts of the body, resulting in a situation of supply-demand mismatch. Heart failure can also result due to abnormal relaxation of the heart muscle (Diastolic dysfunction). Most patients who present with acute heart failure have an exacerbation of chronic heart failure. More than 50 % of heart failure patients can have preserved left the ventricular function. The symptoms are breathlessness, tiredness, cough, reduced urine output, swelling of feet, weight gain and obtundation.
The most common cause is coronary artery disease and heart attacks. The other causes are various cardiomyopathies, myocarditis, hypertension, diabetes mellitus, hyperthyroidism, valvular heart disease, heart rhythm disorders, alcohol abuse and cancer chemotherapy.
The goal of therapy is to improve quality of life, prevent frequent hospitalisation and sudden death. ACE inhibitors, ARBs, diuretics, cardio-selective beta blockers, vasodilators along with anti-platelets are the usual medicines prescribed. Some patients improve with inotropic drugs such as dobutamine and levosimendan.
Interventions other than medical therapy for heart failure:
Ultrafiltration: It is recommended in patients with refractory heart failure not responding to usual medical therapy
Pacemaker implantation: Maintaining normal chronotropic response and atrioventricular synchrony is particularly important for patients with heart failure. Dual chamber pacemakers are useful especially in patients with high-grade AV block and bradycardia
Automatic Implantable Cardioverter Defibrillators (AICD): It is recommended for patients with reduced ejection fraction due to previous myocardial infarction, non-ischemic cardiomyopathy and history of ventricular arrhythmias. Sudden cardiac death (SCD) is 5-10 times more common in heart failure patients than in the general population. AICD placement results in a remarkable reduction in SCD in patients with heart failure. The timing of this intervention and the risk level at the time of implantation may modify the clinical outcome in an individual patient.
Cardiac resynchronization therapy (CRT) / Biventricular pacing: Patients with heart failure and prolonged QRS duration in ECG are candidates for CRT. It aims at improving cardiac performance by restoring the electrical and mechanical dys-synchrony of the heart muscle.
Combination of CRT+AICD: This may be beneficial for patients with arrhythmias, low EF, prolonged QRS in ECG and heart failure. This therapy has been shown to reduce mortality.
Surgical Therapy: a) Revascularisation such as CABG surgery has been shown to be beneficial in patients with heart failure and underlying coronary artery disease, especially in those with evidence of substantial viable myocardium. It reduces mortality and improves the NYHA class of symptoms by favourably altering the LV geometry and increasing LVEF.
b) Valve surgery should be appropriately timed in patients with underlying mitral or aortic valve disease as a cause of heart failure. Though LV dysfunction and heart failure place them at high risk, appropriate valve repairs, reconstructions, replacements at the appropriate time may help improve outcome in patients.
c) Ventricular restoration surgeries have been shown to be beneficial in patients with LV aneurysm. Following a transmural myocardial infarction, left ventricle remodels pathologically, altering its geometry and losing its efficacy as a pump. Batista procedure (reduction left ventriculoplasty) was used in the past and Dor’s aneurysmorrhaphy is in use now-a days.
Extracorporeal Membrane Oxygenerator (ECMO): In some cases of extreme cardiopulmonary failure, complete support with ECMO provides both oxygen and circulation of blood thereby allowing the heart and lung to recover. It can be used for 3-10 days.
Ventricular Assist Devices (VAD): They are invaluable tools in heart failure. LVAD, RVAD and BiVAD are available. They can serve as a bridge to recovery especially in patients with acute heart failure secondary to myocarditis and postcardiotomy status. In end-stage heart failure, they can serve as a bridge to cardiac transplantation. They are also used as destination therapy to improve quality of life in patients where no definitive therapy is planned and who are not candidates for cardiac transplantation.
Heart Transplantation: It is the last resort therapy after failure of other measures to control symptoms/signs. The patient must be well motivated and emotionally stable. Careful selection of the donor and recipient is critical for a good outcome.
Total Artificial Heart: The technology is still immature despite the efforts of more than forty years to develop a fully artificial heart. But this may be the future.