Monitoring
A lifelong follow-up is generally required in patients with hypertrophic cardiomyopathy in order to identify changes in symptoms or development of adverse events and to evaluate risk for atrial fibrillation or sudden cardiac death. The frequency of a patient's monitoring is based upon the age, symptoms, and disease severity. On routine follow-up, it is recommended that patients have a 12-lead ECG, TTE, and 24- to 48-hour Holter monitoring whenever there are new or changed symptoms; every 1-2 years if the pediatric patient is clinically stable (every 3-5 years in adults); an exercise test annually if there are progressive symptoms, every 2-3 years if the patient is clinically stable; and a cardiac MRI every 2-3 years if there are progressive symptoms, every 5 years if the patient is clinically stable.
Transesophageal echocardiography within 3-6 months after septal reduction therapy is recommended to evaluate the efficacy of therapy. Serial clinical assessment, ECG and cardiac imaging are recommended in individuals (every 1-2 years in pediatric patients and every 3-5 years in adults) who are genotype-positive, phenotype-negative for hypertrophic cardiomyopathy. Non-invasive assessment for risk of sudden cardiac death is recommended every 1-2 years and should include evaluation of its risk factors.
Prognosis
The life expectancy is normal or near-normal in most patients with hypertrophic cardiomyopathy, though without the possibility of remission; mortality is often due to embolic stroke, heart failure, and sudden cardiac death.
Complications
Sudden Cardiac Death
Hypertrophic Cardiomyopathy_Follow Up
Hypertrophic cardiomyopathy is the most common structural cause of sudden cardiac death in individuals <35 years old and competitive athletes. Sudden cardiac death can occur in 1% of patients annually. This happens most commonly in hypertrophic cardiomyopathy during or immediately post exercise, though it may also happen at rest.
Major risk factors for sudden cardiac death include the following: Family history of premature sudden cardiac death, cardiac arrest, or sustained ventricular arrhythmias; unexplained syncope (probably arrhythmic by clinical history); LV wall thickness ≥30 mm, LV systolic dysfunction (ejection fraction <50%), LV apical aneurysm; prior episodes of confirmed non-sustained ventricular tachycardia (≥3 consecutive ventricular beats at a rate of ≥120 beats/minute lasting <30 seconds) on continuous ambulatory ECG; and prior cardiac arrest or sustained ventricular arrhythmias (secondary prevention).
Studies have also shown other risk modifiers to be considered in evaluating the risk of sudden cardiac death which include: Age <21 years at presentation; abnormal blood pressure (BP) response to exercise (increase in systolic BP [SBP] <20 mmHg, without rise, or a decrease in BP >20 mmHg during exercise, or a disproportionate decrease in BP immediately after exercise); increased size of left atrium; the presence of myocardial ischemia; LVOTO ≥30 mmHg at rest or with provocation; the presence of extensive LGE on cardiac MRI; and the presence of >1 mutation (double, compound, or triple mutations).
Hypertrophic cardiomyopathy Risk-SCD is a risk prediction model that calculates a patient’s 5-year risk of sudden cardiac death, and it compares favorably with CHA2DS2-VASc scoring system. This is recommended for primary prevention in patients ≥16 years old with no history of resuscitated ventricular tachycardia or fibrillation or spontaneous sustained ventricular tachycardia resulting in syncope or hemodynamic compromise; patients <16 years old may be assessed for primary prevention with pediatric-specific risk prediction models (eg hypertrophic cardiomyopathy Risk-Kids) to estimate the 5-year risk of sudden death. It is useful to discuss the estimated 5-year risk of sudden death and mortality rates when deciding for ICD placement in patients with hypertrophic cardiomyopathy with ≥1 major risk factors for sudden cardiac death. ICD is the only effective means of sudden cardiac death prevention and is recommended for patients with a life expectancy of ≥1 year, spontaneous sustained ventricular tachycardia resulting in syncope or hemodynamic compromise, or previously documented cardiac arrest due to ventricular tachycardia or fibrillation. This should be considered in patients with a hypertrophic cardiomyopathy-risk score of ≥6% estimated 5-year risk of sudden cardiac death. It is reasonable to offer to adult patients with hypertrophic cardiomyopathy with ≥1 major risk factors for sudden cardiac death. Consider the physician's clinical judgment and the patient’s wishes when planning prophylactic ICD therapy based on the above risk factors.