FDA approval Based on the results of the pivotal FIX-HF-5C trial, the FDA approved cardiac contractility modulation therapy for use in the United States on March 21, 2019.
FDA indication The FDA approved the OPTIMIZER Smart System, which delivers cardiac contractility modulation therapy, as indicated to improve 6-minute hall walk distance, quality of life, and functional status of NYHA Class III heart failure patients who remain symptomatic despite guideline directed medical therapy, who are in normal sinus rhythm, are not indicated for cardiac resynchronization therapy, and have a left ventricular ejection fraction ranging from 25% to 45%.
CE mark Based on the results of clinical trials, cardiac contractility modulation devices are approved and available for clinical use in all
European Union countries and in
Australia,
Turkey,
India and
Hong Kong, as well as in other countries that recognize
CE marking for
medical devices.
CE indication as seen on an ECG. The QRS complex is shown in the center.Based on the approval of cardiac contractility modulation devices, the therapy is a treatment option for patients that are at least 18 years old who suffer from
heart failure symptoms due to left ventricular systolic dysfunction (LVSD) despite adequate medical treatment. Further clinical research are under way to identify which patient group within the scope of the device approval benefits most from cardiac contractility modulation treatment. Criteria for the classification of patients with left ventricular systolic heart failure include the severity of the disease based on functional parameters (NYHA classification), the average percentage of
blood volume ejected by the left ventricle with each heart beat (left ventricular
ejection fraction or LVEF) and the duration of the QRS complex seen in the electrocardiogram (ECG). Most clinical studies on cardiac contractility modulation therapy have involved heart failure patients who were classified initially as NYHA Class II, III or IV and had a normal QRS duration (QRS duration ≤ 120 ms). The efficacy of cardiac contractility modulation on patients in an earlier stage of heart failure has not yet been studied. A subsequent evaluation study (subgroup analysis) has already suggested a particular patient group that responds exceptionally well to cardiac contractility modulation therapy. The patients were characterized by a disease severity of NYHA class III and a left ventricular ejection fraction of ≥ 25%. Although studies on cardiac contractility modulation therapy have focused on patients with a normal QRS duration (i.e. ≤ 120 ms), it is possible to use the therapy in patients who meet the treatment indication but who do not have a normal QRS duration. A preliminary study has previously shown that cardiac contractility modulation may be safe and effective in such patients who have not responded to
cardiac resynchronization therapy (CRT).
Therapeutic gap Cardiac resynchronization therapy (CRT; also known as biventricular pacing) has proven to be an effective treatment in heart failure. However, CRT is generally recommended exclusively for patients with a preserved sinus rhythm and a prolonged QRS complex (≥ 120 ms) who also suffer from
left bundle branch block (LBBB), or for patients without left bundle branch block but who have a preserved sinus rhythm and a QRS complex with a width of ≥ 150 ms.
Recommendations The
guidelines issued by the
European Society of Cardiology (ESC) in 2016, mention cardiac contractility modulation therapy as a therapy option to be considered in selected group of patients with HF. Mostly these guidelines are endorsed by national cardiac societies in individual countries within the European Union.
Efficacy Cardiac contractility modulation has proven to be effective and safe in randomized controlled trials involving several hundred patients. The nature and extent of the effect of cardiac contractility modulation have been the subject of numerous investigations. Although various individual publications, as well as one of two meta-analyses, have presented the efficacy and significant potential of cardiac contractility modulation in the treatment of heart failure, medical evaluation of the therapy efficacy is not yet complete. Scientists point out, however, that this was also the case for CRT therapy when it was first introduced, advocating the provision of cardiac contractility modulation to suitable patients before further studies are completed. a large number of review articles (e.g.) and at least two survey articles on device-based treatments of advanced heart failure Further randomized controlled trials studying the effect of cardiac contractility modulation on the progression of heart failure have been initiated and are currently (as of February 2015) recruiting patients. and the
6-minute walk test. The quality of life of participating patients, measured by the Minnesota Living with Heart Failure Questionnaire (MLWHFQ), also improved significantly. However, both meta-analyses demanded additional and larger randomized controlled trials in order to evaluate the effect of the therapy more precisely. Giallauria et al. describe the success of cardiac contractility modulation and the further potential of the therapy. Particular emphasis is given to the possibility that cardiac contractility modulation therapy may close the
therapeutic gap in heart failure treatment if previous study outcomes are confirmed.
Long-Term Survival Studies As of February 2015, the effect of cardiac contractility modulation therapy on the long-term mortality rates of heart failure patients has not been studied in a randomized controlled trial. Some preliminary single-center studies have been reported though. which is based on the records of over 39,000 heart failure patients. Unlike a previous long-term outcome study of cardiac contractility modulation, this study was not limited by a widely heterogeneous group of patients. Following long-term observation, the study concluded that cardiac contractility modulation improved quality of life, exercise tolerance, NYHA class, left ventricular ejection fraction (LVEF) and
brain natriuretic peptide (BNP) levels. Mortality rates were significantly lower than predicted at year 1, and lower than predicted but not statistically significant at year 3.
General Heart failure is a chronic disease that usually progresses gradually. Leisure, travel (by car, train, ship or plane), hobbies and sex life will not be restricted. The patient may perceive an improved capacity for these activities and overall enhanced performance and exercise capacity in response to the actual therapy. ==Contraindications==