The Nordic Baltic Chronic Total Occlusion (CTO) Arrhythmia Study

Chronic Total Coronary Occlusion; Arrhythmia in Patients With Adjunction of PCI to Optimal Medical Treatment Versus Optimal Medical Treatment and in Patients With Failed PCI.

In patients with a chronic total coronary occlusion (CTO ), clinically significant arrhythmia seems to be an important and a poorly investigated problem. The arrhythmia prevalence in an all-comer CTO-population is unknown, but in ICD-populations with ischemic heart disease, a CTO may be found in half of patients with life-threatening arrhythmia.The purpose of the CTO-ARRHYTHMIA study, is to investigate the incidence of clinically significant arrhythmias in CTO patients using an implantable loop recorder. Further, the investigators intend to identify predictors for arrhythmias as well as the impact on arrhythmia of optimized pharmacological treatment and revascularization in CTO patients.

Study Overview

• Status: Active, not recruiting
• Conditions: Chronic Total Coronary Occlusion
• Intervention / Treatment: Procedure: PCI

Detailed Description

In angiographic materials, chronic total coronary occlusion (CTO) is present in approximately 15-25% of patients and in 25-50% of those with significant coronary disease. Until recently, because of low procedural success and increased risk of complications, PCI was a problematic treatment in these patients. The introduction of drug eluting stents and a variety of dedicated CTO devices combined with the evolution of specific CTO techniques have made revascularization by PCI a promising treatment.

In CTO patients, clinically significant arrhythmia seems to be an important and a poorly investigated problem. The arrhythmia prevalence in an all-comer CTO-population is unknown, but in ICD-populations with ischemic heart disease, a CTO may be found in half of patients with life-threatening arrhythmia. Further, in patients with ischemic heart disease receiving ICDs as primary prevention, presence of a CTO was an independent predictor of occurrence of ventricular arrhythmias, and in survivors of out-of-hospital cardiac arrest, the risk of ventricular arrhythmias was found to be increased in patients with a chronic total coronary occlusion. Nevertheless, the genesis of arrhythmia in CTO-patients is likely to be multifactorial. It has been documented, that ischemic heart disease patients who present with a chronic occlusion of at least one coronary artery are older and have additional risk factors such as hypertension, diabetes, lower left ventricular ejection fraction (LVEF) and more frequent myocardial infarction, i.e. a higher Chads2Vasc score (risk score for stroke in atrial fibrillation patients). Although LVEF is lower in patients with a chronic coronary occlusion, less than 1/3 are potential ICD candidates with an LVEF <35%. However, a recent study in consecutive post-AMI survivors documented the highest incidence of sudden cardiac death in patients with a relatively preserved LVEF.

The purpose of the CTO-ARRHYTHMIA study, is to investigate the incidence of clinically significant arrhythmias in CTO patients using an implantable loop recorder. Further, the investogators intend to identify predictors for arrhythmias as well as the impact on arrhythmia of optimized pharmacological treatment and revascularization in CTO patients. Here, CTO patients with failed PCI may be individuals with a particularly high risk of severe arrhythmias.

• Study Type: Interventional
• Enrollment (Estimated): 200
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • North Denmark
    • Aalborg, North Denmark, Denmark, 9000
      • Aalborg University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• ≥1 CTO lesion amenable to PCI.
• Stable or stabilized coronary artery disease.
• Angiographic/echocardiographic signs of reversible perfusion.
• CTO lesion in a coronary vessel supplying a significant myocardial territory (vessel diameter usually ≥3mm).

Exclusion Criteria:

• Expected survival <1 year.
• Patients with an indication of ICD due to EF < 35 or previous ventricular tachycardia.
• Patients with a cardiac device i.e. ICD, pacemaker or cardiac resynchronizing treatment device.
• Renal failure on dialysis.
• Lesions treated with PCI within one month.
• Indication for coronary artery bypass grafting (CABG). I.e. Two-or three vessel disease or left main disease and a syntax score >22.
• Significant valvular heart disease.
• Declined informed consent.
• Regarding CMRI: allergy to contrast medium, severe obesity, claustrophobia and certain metallic implants.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Optimal Medical Treatment; CTO patients receiving optimal medical treatment
Active Comparator: Optimal Medical Treatment and PCI; CTO patients receiving PCI in ajunction to optimal medical treatment	Procedure: PCI; A loop recorder is implanted i all patients in both study groups to investigate: Prevalence and severity of cardiac arrhythmias.; Effect on detected arrhythmia, in particular ventricular tachyarrhythmia, of optimal medical therapy vs. coronary revascularization by PCI.; Prevalence and severity of cardiac arrhythmias in CTO-patients with failed PCI.; Indication for prophylactic ICD implantation in CTO-patients treated conservatively or by PCI and after failed PCI.; Relation of arrhythmias to angina pectoris symptoms (CCS class), Quality of life questionnaire results and presence of myocardial reversible perfusion defects by CMRI.; Other Names: Loop recorder

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of clinically significant arrhythmias	Rate og clinically significant arrhythmias in PCI versus medically only treated patients by loop recorder (table 1) and in patients with failed PCI.	1 year

Collaborators and Investigators

• Sponsor: Leif Thuesen
• Investigators: Study Chair: Peter Soegaard, DMSc, Co-PI

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2020
• Primary Completion (Actual): October 1, 2025
• Study Completion (Estimated): September 1, 2027

Study Registration Dates

• First Submitted: September 3, 2020
• First Submitted That Met QC Criteria: September 3, 2020
• First Posted (Actual): September 9, 2020

Study Record Updates

• Last Update Posted (Actual): March 20, 2026
• Last Update Submitted That Met QC Criteria: March 18, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Myocardial Ischemia; Heart Diseases; Cardiovascular Diseases; Vascular Diseases; Coronary Disease; Coronary Occlusion
• Other Study ID Numbers: CTO-ARRHYTHMIA

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Data will be analyzed at site

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No