Randomized controlled trial of remote ischemic preconditioning and atrial fibrillation in patients undergoing cardiac surgery

Table 1 Society of thoracic surgery definitions for peri-operative outcomes

Outcomes	Definition
Stroke	If the patient had a central neurological deficit persisting postoperatively for > 72 h
Peri-operative MI	0-24 h post-operative: The CK-MB (or CK if MB not available) must be greater than or equal to 5 times the upper limit of normal, with or without new Q waves present in two or more contiguous ECG leads No symptoms required > 24 h post-operative: Indicate the presence of a peri-operative MI (> 24 h post-op) as documented by at least one of the following criteria: (1) Evolutionary ST-segment elevations (2) Development of new Q-waves in two or more contiguous ECG leads (3) New or presumably new LBBB pattern on the ECG (4) The CK-MB (or CK if MB not available) must be greater than or equal to 3 times the upper limit of normal

MI: Myocardial infarction; ECG: Electrocardiogram.

Table 2 Baseline characteristics between control group and remote ischemic preconditioning group

Characteristic	Control (n = 51)	RIPC (n = 51)	P
Demographics
Mean age (± SD)	68.9 (± 9.8)	69.4 (± 9.9)	0.77
Male % (n)	62.8 (32)	76.5 (39)	0.20
Caucasian % (n)	88.2 (45)	90.2 (46)	1.00
Mean BMI (± SD)	30.4 (± 7.6)	28.4 (± 5.2)	0.13
Co-morbidities
Diabetes mellitus % (n)	39.2 (20)	62.7 (32)	0.029
Hypertension % (n)	84.3 (43)	82.4 (42)	1.00
Dyslipidemia % (n)	90.2 (46)	90.2 (46)	1.00
Heart failure % (n)	21.6 (11)	23.5 (12)	1.00
Atrial fibrillation % (n)	0.0 (0)	0.0 (0)	NA
AICD % (n)	0.0 (0)	2.0 (1)	1.00
CVA % (n)	3.9 (2)	5.9 (3)	1.00
TIA % (n)	2.0 (1)	7.8 (4)	0.36
PAD % (n)	9.8 (5)	21.6 (11)	0.17
CKD % (n)	23.5 (12)	23.5 (12)	1.00
Dialysis % (n)	2.0 (1)	2.0 (1)	1.00
Mean creatinine (± SD)	1.2 (± 1.1)	1.2 (± 0.7)	0.89
COPD % (n)	5.9 (3)	0.0 (0)	0.24
Tobacco use % (n)	17.6 (9)	27.5 (14)	0.34

AICD: Automatic implantable cardioverter-defibrillator; BMI: Body mass index; COPD: Chronic obstructive pulmonary disease; CKD: Chronic kidney disease; CVA: Cerebrovascular accident; TIA: Transient ischemic attack; PAD: Peripheral arterial disease; RIPC: Remote ischemic preconditioning.

Table 3 Baseline medications and clinical presentation in the control group and remote ischemic preconditioning group

Characteristic	Control (n = 51)	RIPC (n = 51)	P
Medications % (n)
Alpha blockers	7.8 (4)	2.0 (1)	0.36
Beta blockers	78.4 (40)	80.4 (41)	1.00
ACE-inhibitors	37.3 (19)	41.2 (21)	0.84
Aspirin	90.2 (46)	90.2 (46)	1.00
Statins	84.3 (43)	86.3 (44)	1.00
Clinical presentation % (n)
Stable angina	23.5 (12)	23.5 (12)	1.00
Unstable angina	25.5 (13)	25.5 (13)	1.00
Positive stress test	27.5 (14)	25.5 (13)	1.00
Non-STEMI	19.6 (10)	17.6 (9)	1.00
STEMI	0.0 (0)	2.0 (1)	1.00
Valve without CAD	17.6 (9)	27.5 (14)	0.34

ACE: Angiotensin converting enzyme; CAD: Coronary artery disease; RIPC: Remote ischemic preconditioning; STEMI: ST-elevation myocardial infarction.

Table 4 Clinical outcomes in the control group vs remote ischemic preconditioning group

Characteristic	Control (n = 51)	RIPC (n = 51)	P
Primary endpoint
POAF % (n)	41.2 (21)	54.0 (27)	0.23
Secondary endpoints
Other arrhythmia % (n)	13.7 (7)	11.8 (6)	1.00
MI % (n)	3.9 (2)	0.0 (0)	0.50
Stroke % (n)	0.0 (0)	3.9 (2)	0.24
Mean EF (± SD)	53.1 (± 14.8)	50.5 (± 16.9)	0.43
Bleeding % (n)	21.6 (11)	28.0 (14)	0.50
Mean cross-clamp time (± SD)	88.7 (± 44.8)	93.0 (± 38.5)	0.61
In-hospital mortality % (n)	0 (0)	3.9 (2)	0.50
30-d mortality (after discharge) % (n)	0 (0)	0 (0)	1.0
30-d readmission % (n)	11.8 (6)	16.3 (8)	0.57
Mean LOS (± SD)	13.7 (± 7.8)	14.0 (± 7.7)	0.87

EF: Ejection fraction; LOS: Length of stay; MI: Myocardial infarction; POAF: Post-operative atrial fibrillation; RIPC: Remote ischemic preconditioning; STEMI: ST-elevation myocardial infarction.