Clinical Trial: Implantable Cardiac Monitors in High-Risk Post-Infarction Patients With Cardiac Autonomic Dysfunction

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Implantable Cardiac Monitors in High-risk Post-infarction Patients With Cardiac Autonomic Dysfunction and Moderately Reduced Left Ventricular Ejection Fraction

Brief Summary:

The majority of deaths after myocardial infarction occurs in patients with preserved left ventricular ejection fraction (>35%) for whom no prophylactic strategies exist. Periodic Repolarization Dynamics (PRD) and Deceleration Capacity (DC) of heart rate are autonomic risk markers that identify a new high risk group of patients with LVEF 35-50% who have the same poor prognosis as patients with LVEF ≤35%.

In SMART-MI, post-infarction patients with LVEF 35-50% and abnormal PRD and/or DC will be randomly assigned to biomonitoring-guided therapy or conventional follow-up.


Detailed Summary:

Sudden cardiac death (SCD) is the most common single cause of death in the industrialized world. Patients after myocardial infarction (MI) are at increased risk of SCD. Current guidelines recommend prophylactic ICD-implantation in post-MI patients with reduced left ventricular ejection fraction (LVEF ≤35%). However, the majority of arrhythmic deaths after MI occurs in patients with LVEF >35% in whom no specific prophylactic strategies exist, indicating an important unmet medical need.

There is a large body of evidence that presence of cardiac autonomic dysfunction after MI is associated with an increased susceptibility to malignant brady- and tachyarrhythmias eventually culminating in SCD. Periodic repolarization dynamics (PRD) and heart rate deceleration capacity (DC) are clinically validated autonomic risk markers that provide strong and independent prognostic information in post-MI patients with LVEF >35%. PRD and DC reflect different facets of autonomic function and can therefore be used in combination to predict risk. Previous studies demonstrated that combined assessment of PRD and DC identifies a new high-risk group among post-MI patients with moderately reduced LVEF (36-50%). This new high-risk group has similar characteristics with respect to prognosis and patient numbers as the established high-risk group identified by LVEF ≤35%.

However, the exact mechanisms leading to death in this new high-risk group need to be investigated in order to develop specific preventive strategies. As known from studies with implantable cardiac monitors (ICM) in post-MI patients with LVEF ≤40% eventual death is often preceded by primarily asymptomatic serious arrhythmic events. These data suggest a potential time frame for pre-emptive interventions in case of arrhythmic events, which could improve outcome.


Sponsor: Klinikum der Universitaet Muenchen

Current Primary Outcome: Detection of serious arrhythmic events [ Time Frame: 18 months ]

Time to detection of one of the following serious arrhythmic events: atrial fibrillation ≥6 min, higher degree AV-block ≥ IIb, ventricular tachycardia with a cycle length ≤320ms lasting for ≥12 sec (corresponding to 40 beats), sustained ventricular tachycardia and ventricular fibrillation


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Composite of all-cause mortality, stroke, systemic arterial thromboembolism and unplanned hospitalizations for decompensated heart failure [ Time Frame: 18 months ]
    Time to one of following clinical events: death, stroke, systemic arterial thromboembolism and unplanned hospitalization for decompensated heart failure
  • All cause mortality [ Time Frame: 18 months ]
    Time to death
  • Cardiovascular mortality [ Time Frame: 18 months ]
    Time to cardiovascular death
  • Unplanned hospitalizations for decompensated heart failure [ Time Frame: 18 months ]
    Time to unplanned hospitalizations for decompensated heart failure
  • Sinus arrest >6sec [ Time Frame: 18 months ]
    Time to detection of sinus arrest >6sec
  • Atrial fibrillation ≥6 min [ Time Frame: 18 months ]
    Time to detection of atrial fibrillation ≥6 min
  • Higher degree AV-block ≥ IIb [ Time Frame: 18 months ]
    Time to detection of higher degree AV-block ≥ IIb
  • Non-sustained ventricular tachycardia [ Time Frame: 18 months ]
    Time to detection of ventricular tachycardia with a cycle length ≤320ms lasting for ≥12 sec
  • Sustained ventricular tachycardia / ventricular fibrillation [ Time Frame: 18 months ]
    Time to detection of sustained ventricular tachycardia / ventricular fibrillation


Original Secondary Outcome: Same as current

Information By: Klinikum der Universitaet Muenchen

Dates:
Date Received: October 31, 2015
Date Started: May 2016
Date Completion: August 2018
Last Updated: April 13, 2017
Last Verified: April 2017