Background
Hypertrophic cardiomyopathy (HCM) is a genetic disorder that is typically inherited in an autosomal dominant fashion with variable penetrance and variable expressivity. The disease has complex symptomatology and potentially devastating consequences for patients and their families. [1] The goals of treatment for hypertrophic cardiomyopathy are to relieve symptoms and prevent sudden cardiac death in those at high risk. When HCM is complex with significant comorbidity, such as chronic respiratory failure, it remains even difficult to choose the best treatment.
Case presentation
59 years old woman at the age of 3 years old was diagnosed with poliomyelitis (polio), which was complicated with kyphoscoliosis. Kyphoscoliosis caused chronic respiratory failure. In 2006 dyspnoea and fatigue progressed, obstructive HCM was diagnosed after echocardiographic examination. Despite optimal medical treatment, symptoms were progressing.
The patient was admitted to our hospital on 2012.09.29 due to the: severe dyspnoea at rest, fatique, dizziness, fever ~37.4°C for about a week. There were no abnormal findings on routine blood tests except for arterial blood gas. Compensated respiratory acidosis because of severe lung restriction and hypoventilation due to kyphoscoliosis were diagnosed and Bi-level NPPV was recommended. Respiratory system eventually was compensated, but dyspnoea and fatique were not eliminated. Electrocardiographic monitoring didn’t show ventricular arrhythmias. 2D echocardiography examination revealed severe LV hypertrophy (LVDDi 27,3mm/m², IVS 14mm, LVPW 14mm) with good systolic LV function (EF 60%). Severe LV outflow tract obstruction was found (v max 5,8m/s, G max 138 mmHg), because of septum hypertrophy and systolic anterior leaflet motion (SAM) together with severe mitral regurgitation (III-IV degree). RV was not dilated with the tricuspidal regurgitation I-II degree and systolic pressure in pulmonary artery 35-40mmHg. Normal coronary arteries were found on angiogram.
Assessing compensated respiratory failure, comparing advantages vs. disadvantages of different methods of obstructive HCM treatment, surgical treatment was chosen: septal myectomy through aortotomy was performed and the LVOT obstruction was eliminated. Postoperative 2D echocardiographic examination revealed laminar flow in LV outflow tract, no MV regurgitation and good LV systolic function (EF 60%). Despite successful cardiac surgery results, hemodynamic remains unstable because of pneumonia and respiratory failure.
Current guidelines
Treatment of HCM requires a thorough understanding of the complex, diverse pathophysiology and must individualized to the patient. All the comorbidities that may contribute to the cardiovascular disease must be treated (1). Hydration and avoidance of environmental situation where vasodilatation may occur are important in asymptomatic patients. High doses of diuretics and vasodilators should be avoided.
The main goal of pharmacological treatment in symptomatic pts is to alleviate symptoms. Betablockers are the mainstay of the pharmacological treatment because of their negative inotropic effect. Verapamil therapy is recommended for the treatment of symptoms in patients who do not respond to beta blocking drugs or who have side effects or contraindications to beta blocking drugs (class I, level of evidence: B).
If the symptoms persist despite optimal medical therapy, the alternative treatment for patients with obstructive HCM is a dual chamber (DDD) pacing (class IIb, level of evidence:B) as an opportunity to decrease the LVOT gradient (improvement in symptoms) in patients who are suboptimal candidats for septal reduction therapy. Although there was an initial enthusiasm for dual chamber pacing as a primary treatment for pts with obstructive CMP, the studies demonstrated long lasted beneficial results in only a small minority of patients and the improvement was judged to be a placebo effect.
Still there is the discussion between advantages of alcohol septal ablation and surgical myectomy. Ablation is minimal invasive treatment, with survival free from recurrent symptoms 71%, with mortality rate less than 4% and is safer in the patients with significant comorbidities or advanced age. Septal ablation is dependent on the variable septal artery anatomy, which may not supply the targeted area of the septum in up to 20-25% of patients, may be complicated with high-grade AV block, requiring permanent pacemakers. There is no opportunity to repair MV regurgitation and systolic anterior motion. Transaortic septal myectomy is currently considered most appropriate treatment for the majority of patients with obstructive HCM and severe symptoms unresponsive to medical therapy. Surgical results improved in recent years – technical success is 90-95%, survival free from recurrent symptoms is 89%, muscle is directly visualized and resected and there is an opportunity to repair MV. Still significant comorbidity reveals big mortality risk (2)
References
1.Ly HQ; Greiss I; Talakic M; Guerra PG; Macle L; Thibault B; Dubuc M; Roy D, Clinical Electrophysiology Service, Department of Medicine, Montreal Heart Institute, University of Montreal, Montreal, et al. Sudden death and hypertrophic cardiomyopathy: a review. Can J Cardiol. 2005; 21(5):441-8 (ISSN: 0828-282X).
2.Gersh B, Maron B.J., Dearani J.A. et al. 2011 ACCF/AHA Guideline for the Diagnosis and Treatment of Hypertrophic Cardiomyopathy JACC, 2011;56: e212-260.
Expert’s comments:(Written authorization required from each expert)
1. Grzegorz Kopeć MD, PhD
The management of patients with hypertrophic cardyomiopathy includes screencing and counselling of other family members, management of symptoms, and prevention of disease related complications. Screening in family members is reccomended at intervals of 12-18 months usually up to the age of 18 to 21 years and every 5 years thereafter. Beta blockers are the first line drugs to relieve the symptoms of chest pain, despnoea and presyncope on exertion in obstructive hypertrophic cardyomiopathy. Werapamil is also used for symptoms but must be used with caution in the presence of very high gradient in the left ventricular outflow tract and in patients with pulmonary hypertension due to the risk of rapid clinical deterioration. When the drugs are not tolerated or not effective surgical myotomy-muectomy is the treatment of choice. In patients with high risk of sudden cardiac death an insertion of implantable cardiovarter defibrilator is needed
2. Paweł Rubiś MD, PhD
The presented patient possess a great challenge for the managing physicians. Not only the patient has advanced HCM with left ventricular outflow tract (LVOT) obstruction but also concomitant severe pathology of spinal column, causing respiratory failure and predisposing to frequent respiratory tract infection. Definitely multi-disciplinary approach is recommended, including cardiologists, familiar with HCM complex management, cardiac surgeon, anesthetists, pulmonologists, and orthopedists. There are two difficult issues that should be simultaneously addressed. Firstly, the optimal management of HCM with severe LVOT obstruction and secondly, what is the best option for respiratory failure. There are two accepted methods of reliving LVOT obstruction, either percutaneous or surgical. The advantage of surgical approach is that concomitant pathology of mitral valve can be corrected which is offset by slightly higher peri-procedural mortality and long rehabilitation process. The chosen surgical operation is probably better for the patient as apart from septal incision, SAM phenomenon was corrected. As for the further patient management, it is much more complex and no clear guidelines exists. The deformation of spinal column should be assessed, probably with magnetic resonance and well-thought, realistic decision if anything can be corrected, made. However, if surgical correction is not feasible, only rehabilitation and avoidance of infection are the only reasonable choices.
3. Prof. Piotr Podolec, MD, PhD
Unfortunately, we face severely ill and complex patient without clear guidance on the optimal management. The patient’s symptoms are an interplay of advanced HCM with LVOT obstruction and possibly concomitant mitral valve pathology as well severe respiratory failure due to kyphoscoliosis. Being cardiologists, it is much easier for me to make recommendations on HCM therapy. Given the fact that surgical myomectomy and correction of mitral valve is a more effective and durable procedure than alcohol septal ablation, I would advocate on surgical management. However, before any final decision, the patient should be thoroughly assessed with regards to his respiratory status and chances that his kyphosoliosis will not exacerbate or even impede his post-operative recovery. Although difficult, this decision is relatively simple to make and everything is in the hands of highly experienced surgical and anesthetists team. Much more complex is decision on optimal management of respiratory failure. I think that we cannot answer this question without precise assessment of kyphosloliosis with magnetic resonance. Then the feasibility of surgery should be assessed by experienced orthopedists. Provided that HCM will be satisfactory corrected and patient recovers from surgery, he should be once again discussed and eventual decision to proceed with spinal column surgery made. Personally, I am not an optimist but it is at least worth trying, otherwise we risk progressive respiratory failure and even pulmonary hypertension, which would be an ominous sign.
Expert’s conclusions:
HCM is a common genetic cardiovascular disease. Despite that, there are no standard recommendations for HCM – every patient is opportunity for choosing a different treatment.
Authors:
Prof. R.Benetis MD, PhD1, Prof. E.Ereminienė MD, PhD1, Prof. N.Stoškutė1,Assist. Prof. S.Miliauskas MD, PhD1, Prof. R.Ordienė, MD1, D.Hoppenot, M.D. PhD1.
Experts:
Grzegorz Kopeć MD2, PhD, Paweł Rubiś MD, PhD2, Prof. Piotr Podolec MD, PhD3
1Hospital of Lithuanian University of Health Sciences Kaunas Clinics: department of Cardiology;
– department of Pulmonology and Immunology.
2Department of Heart and Vascular Disease, John Paul II Hospital, Kraków, Poland
3Department of Cardiac and Vascular Disease in John Paul II Hospital, Institute of Cardiology, Faculty of Medicine, Jagiellonian University, Krakow, Poland.
