Table 2

Outcomes evaluated and results

Study IDDescription of reference groupOutcomes evaluated and timing of assessmentResults
Aro et al4≤200 msFollow-up for 30 yearsMultivariate adjusted HR:

  • All-cause mortality: 140/222 vs 5933/10 563, HR 1.05 (0.89 to 1.24)

  • Cardiovascular mortality: 44/222 vs 1904/10 563, HR 0.94 (0.70 to 1.27)

  • Heart failure: 42/222 vs 1673/10 563, HR 1.22 (0.90 to 1.65)

  • CAD: 74/222 vs 3465/10 563, HR 0.97 (0.77 to 1.22)

  • Atrial fibrillation: 35/222 vs 1591/10 563, HR 1.03 (0.74 to 1.45)

  • TIA or stroke: 50/222 vs 1877/10 563, HR 1.23 (0.92 to 1.62)

Cheng et al12≤200 msUp to 35 yearsAtrial fibrillation: 25/124 vs 456/7451, multivariate HR 2.36 (1.53 to 3.64)
Pacemaker insertion: 26/124 vs 98/7451, multivariate HR 4.32 (2.46 to 7.59)
All-cause mortality: 62/124 vs 1677/7451, multivariate HR 1.48 (1.10 to 1.99)
Crisel et al19<220 msUp to 5 yearsHeart failure: 26/87 vs 97/851, adjusted for medications HR 2.33 (1.49 to 3.65)
Cardiovascular mortality: 15/87 vs 52/851, adjusted for medications HR 2.33 (1.28 to 4.22)
All-cause mortality: 42/87 vs 243/851, adjusted for medications HR 1.58 (1.13 to 2.20)
Heart failure or cardiovascular mortality: 34/87 vs 122/851, adjusted for medications HR 2.43 (1.64 to 3.61)
Heart failure: 26/87 vs 97/851, adjusted for heart failure HR 2.02 (1.24 to 3.31)
Cardiovascular mortality: 15/87 vs 52/851, adjusted for heart failure HR 2.29 (1.18 to 4.45)
All-cause mortality: 42/87 vs 243/851, adjusted for heart failure HR 1.49 (1.04 to 2.14)
Heart failure or cardiovascular mortality: 34/87 vs 122/851, adjusted for heart failure HR 2.09 (1.36 to 3.23)
Erikssen and Otterstad10≤210 msMI, angina pectoris, pathological exercise ECG, death from CHD, total CHD eventsMI: 6/98 vs 54/1537
Angina pectoris: 3/98 vs 76/1537
Pathological exercise ECG: 7/98 vs 205/1537
Death from CHD: 1/98 vs 36/1537
Total deaths: 3/98 vs 71/1537
Hisamatsu et al17<220 msAll-cause mortality, cardiovascular disease mortality, CHD mortality, stroke mortality with mean follow-up of 24.3 yearsAll-cause mortality: total events 3269/9051, multivariate HR 1.06 (0.85 to 1.31)
Cardiovascular disease mortality: total events 1101/9051, multivariate HR 0.94 (0.65 to 1.37)
CHD mortality: total events 227/9051, multivariate HR 1.49 (0.76 to 2.92)
Stroke mortality: total events 491/9051, multivariate HR 0.70 (0.37 to 1.31)
Knuiman et al20Unclear, not long PR intervalIncident atrial fibrillation at follow-up of 15 yearsIncident atrial fibrillation: total events 343/4267, multivariate HR 1.29 (0.68 to 2.44)
Kobayashi et al21<220 msCardiovascular disease, CHD and stroke at 13.1 years follow-upAll cardiovascular disease: total events 421/5425, multivariate HR 2.98 (1.22 to 7.31)
CHD: total events 180/5425, multivariate HR 1.57 (0.22 to 11.42)
Stroke: total events 241/5425, multivariate HR 3.90 (1.42 to 10.72)
Cerebral infarction: total events 144/5425, multivariate HR 2.98 (1.22 to 7.31)
Magnani et al22≤200 msIncident heart failure, atrial fibrillation and all-cause mortalityIncident heart failure: total events 369/2722, multivariate HR 1.46 (1.11 to 1.93)
Incident atrial fibrillation: total events 537/2722, multivariate HR 1.26 (0.99 to 1.61)
All-cause mortality: total events 832/2722, multivariate HR 1.14 (0.94 to 1.39)
Nielsen et al13<200 msAtrial fibrillation at median follow-up of 5.7 yearsIncident atrial fibrillation: total events 11 087/288 181, multivariate HR 1.26 (1.17 to 1.35) (reference group PR interval 150–161 ms)
Men multivariate HR 1.18 (1.06 to 1.30) and women multivariate HR 1.30 (1.17 to 1.44)
Perez et al14≤200 msIncident atrial fibrillation at 5.3 yearsRisk of atrial fibrillation with PR >200 ms: total events 1050/42 751, multivariate HR 1.3 (1.1 to 1.6)
Rajala et al11<220 msMortality at 5 years follow-upCrude 5 years mortality: first-degree heart block 20/39 vs normal 453/657
Soliman et al151 SD change and upper 5th centile vs 95th centile of PR durationIncident atrial fibrillation and ischaemic stroke with follow-up of 6.97 yearsTotal atrial fibrillation events 117/15 429. Total ischaemic stroke events 599/15 429
Risk of ischaemic stroke with 1 SD change in PR duration: multivariate HR 1.00 (0.92 to 1.08)
Risk of atrial fibrillation with 1 SD change in PR duration: multivariate HR 1.41 (1.20 to 1.65)
Risk of atrial fibrillation with upper 5th centile vs 95th centile of PR duration: multivariate HR 1.59 (0.77 to 3.30)
Soliman et al23≤200 ms for crude analysis but adjusted analysis 120–200 msMortality at median follow-up of 13.8 yearsProlonged PR interval and mortality: 325/654 vs 2216/6847
High-P duration prolong PR interval and mortality: multivariate HR 2.00 (1.34 to 2.99)
Low-P duration prolong PR interval and mortality: multivariate HR 0.99 (0.86 to 1.14)
Uhm et al16≤200 msAdvanced AV block, sick sinus syndrome, atrial fibrillation, LV dysfunctions follow-up period of 9.4 yearsFirst-degree heart block and multivariate outcomes:

  • Advanced AV block: 12/544 vs 26/3272, HR 2.77 (1.38 to 5.59)

  • Sick sinus syndrome: 8/544 vs 277/3272, HR 1.32 (0.61 to 2.84)

  • Atrial fibrillation: 98/544 vs 277/3272, HR 2.33 (1.84 to 2.94)

  • LV dysfunction: 59/544 vs 245/3272, HR 1.49 (1.11 to 2.00)

  • CAD, coronary artery disease; CHD, coronary heart disease; LV, left ventricular; MI, myocardial infarction; TIA, transient ischaemic attack.