Table 1. Patient and procedural characteristics in the studies addressing pacemaker dependency after cardiac surgery.
| Study (Author, year) | Feldman,1992 | Glikson, 1997 | Onalan, 2008 | Huynh, 2009 | Merin, 2009 | Raza, 2011 | Baraki, 2013 | Rene, 2013 |
|---|---|---|---|---|---|---|---|---|
| Study characteristics | ||||||||
| Design, Retrospective (R) or Prospective (P) | R | R | R | R | R | R | P | R |
| Sample size | 36 | 120 | 102 | 15 | 72 | 141 | 138 | 104 |
| Follow up completed (N) | 36 | 86 | 102 | 10 | 58 | 90 | 129 | 98 |
| Follow-up duration (mean months) | 36 | 41 | 32 | 32 | 72 | 67 | 64 | 43 |
| Mortality | - | 38% (46) | - | 20% (3) | 32% (23) | 21% (19) | 33% (45) | - |
| Patient characteristics | ||||||||
| Age (mean years) | - | 72 a | 68 | 70 | 67 | 69 | 71 | 67 |
| Sex (% male) | 92% (33) | 48% (57) | 62% (63) | 60% (9) | 61% (44) | 99% (89) | 66% (65) | |
| Prior cardiac surgery | - | 19% (23) | 8% (8) | - | 11% (8) | 9% (8) | 20% (27) | - |
| Co-morbid conditions | ||||||||
| CAD | 53% (19) | - | 65% (66) | 20% (3) | 49% (21) | 39% (55) | - | |
| LVEF <50% | - | - | 12% (12) | - | 24% (17) | - | 38% (52) | - |
| DM | 88% (23) | - | 23% (23) | 33% (5) | 29% (21) | 28% (25) | 23% (31) | - |
| Preoperative conduction | ||||||||
| LBBB | - | 17% (20) | 9% (8) | 6.7% (1) | 25% (18) | - | 9% (13) | 11% (11) |
| RBBB | - | 12% (14) | 9% (8) | 6.7% (1) | 15% (11) | - | 12% (16) | 7% (7) |
| 1st degree AV block | - | 36% (46) | 13% (12) | 13% (2) | 14% (10) | 34% (31) | 14% (19) | - |
| LAFB | - | 15% (18) | 7% (6) | 0 | 4% (3) | - | 10% (14) | 9% (9) |
| 2+ degree AV block | - | 6% (7) | - | 6.7% (1) | 1% (1) | - | 7% (10) | 0 |
| Normal sinus rhythm | - | 13% (16) | - | 93% (14) | - | 18% (25) | 47% (64) | 82% (80) |
| Atrial Fibrillation | - | 11% (13) | 25% (25) | 6.7% (1) | - | 14% (20) | 17% (23) | - |
| Medications | ||||||||
| Beta-blocker | 0 | - | - | 47% (7) | 51% (37) | - | 25% (34) | - |
| Anti-arrhythmic | - | - | - | - | 21% (15) | - | 8% (11) | - |
| Procedure characteristics | ||||||||
| Procedure type | ||||||||
| AVR | 0 | 23% (28) | 60% (61) | 40% (6) | 53% (38) | - | 100% (138) | 72% (71) |
| MVR | 0 | 5% (6) | 23% (23) | 0 | 25% (18) | - | 0 | 11% (11) |
| Combined AVR/MVR | 0 | 5% (6) | - | 13% (2) | - | 6% (8) | 0 | 10% (10) |
| CABG | 86% (31) | 25% (30) | 63% (64) | 0 | 58% (42) | 30% (43) | 0 | 33% (32) |
| Combined valve + CABG | 14% (5) | 13% (16) | - | 47% (7) | - | 62% (88) | 0 | - |
| Cross-clamp time—minutes (mean) | - | 72 | - | 125 | 92 | 121 | 67 | 82 |
| On-pump time—minutes (mean) | - | 112 | - | 157 | 141 | 168 | 104 | - |
| Pacemaker placement | ||||||||
| Indications | ||||||||
| Complete heart block | 72% (26) | 54% (65) | 70% (71) | 87% (13) | 82% (59) | 55% (78) | 75% (103) | 100% (98) |
| Slow atrial fibrillation | 0 | 7% (8) | 11% (11) | 0 | 13% (9) | 25% (35) | 16% (22) | 0 |
| Sinus node dysfunction | 28% (10) | 11% (13) | 20% (20) | 13% (2) | 20% (28) | 2% (3) | 0 | |
| Mobitz II 2nd degree block | 0 | 3% (4) | - | 0 | 3% (2) | 0 | ||
| Timing of PM implantation (median days post-op) | - | 11 | 10 | 6 | 13 | 7 | 7 | 6 |
Reported values represent percentage of patients in each category, with numbers in parentheses, unless specified. Abbreviations: AVR–aortic valve replacement, MVR–mitral valve replacement, CABG–coronary artery bypass grafting, CAD–coronary artery disease, LVEF–left ventricular ejection fraction, DM–diabetes Mellitus, LBBB—left bundle branch block, RBBB–right bundle branch block, PM–pacemaker, preop–preoperative, postop–postoperative
a Median