Table 1 Patient characteristics, ECG findings, and clinical events

Patient characteristics

 Number of patients recruited

111 (13 withdrew)

 Number of patients not recruited due to poor quality of ECG recordings or diary documentation

4

 Male

87 (78.4 %)

 Mean age (SD)

68.1 years (8.0)

 Recruited with prognostically significant coronary disease found at cardiac catheterisation

38 (34.2 %)

 Recruited after acute coronary syndrome

73 (65.8 %)

 Mean follow-up period between first and last heart rate recording (SD)

445.6 days (204.6)

 Prescribed a negative chronotropic drug at start of study

92 (82.9 %)

 Mean resting supine heart rate at start of study (SD)

58.4 bpm (9.4)

Number of patients with ECG recordings

 Unsupervised 300-m walk

111 (100 %)

 Unsupervised flight of stairs

82 (73.9 %)

 Angina

43 (38.7 %)

Number of diary-documented events

 Unsupervised 300-m walk (percentage of expected)

6705 (85.4 %)

 Unsupervised flight of stairs (percentage of expected)

4082 (74.2 %)

 Angina

591

Interpretable ECGs for diary-documented events

 Unsupervised 300-m walk^a

5144 (76.7 %)

 Unsupervised flight of stairs^a

3423 (83.9 %)

 Angina

383 (64.8 %)

 Supervised 300-m walk^a

688

 Supervised flight of stairs^a

685

ECG quality (interpretable ECGs)

 ECGs with two heart rate measurements

96.5 %

 Heart rate calculations based on five consecutive R waves

93.4 %

 Mean start of first heart rate calculation (SD)

2.0 s (3.8)

 Mean start of second heart rate calculation (SD)

25.2 s (4.2)

Mean difference in heart rate between the beginning and end of 30-s ECGs

 Rest ECG for unsupervised 300-m walk (SD)

−0.8 bpm (4.0)

 Postexertional unsupervised stairs (SD)

−2.0 bpm (5.7)

 Postexertional unsupervised 300-m walk (SD)

−4.1 bpm (5.0)

 Angina (SD)

−2.0 bpm (5.4)

Clinical events during follow-up

 ST elevation myocardial infarction

0

 Non-ST elevation myocardial infarction (number of patients)

2 (2)

 Unstable angina (number of patients)

6 (5)

 Coronary death diagnosed postmortem

1