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Prevalence of Known and Incidental Atrial Fibrillation in a Relatively Healthy Population Aged Over 40
S212
Abstracts
ABSTRACTS
stable coronary artery disease, and is significantly associated with adverse long-term cardiovascular outcomes. The aim of our study was to investigate baseline troponin (both 4th generation and hs-TnT) concentrations in high-risk patients undergoing elective non-cardiac surgery. Methods: Consecutive patients undergoing elective non-cardiac surgery, currently prescribed anti-platelet therapy because they were deemed high risk, were included. Patient demographics and comorbidities were collected. Baseline hs-TnT (Roche Diagnostics, ninetyninth percentile 13 ng/L, limit of detection 2 ng/L), and fourth generation TnT (Roche Diagnostics, 99th percentile 10 ng/L, limit of detection 10 ng/L) were collected in all patients. Results: One hundred and ten consecutive patients were recruited (mean age: 72 ± 9.7 years, 64% male). Hs-TnT concentration was elevated above the ninety-ninth percentile in 29 (26%) patients, with only seven (6%) elevated using the older fourth generation assay. Multivariate predictors of elevated hs-TnT included; age (r = 0.42, p < 0.01); estimated glomerular filtration rate (r = −0.67, p < 0.01); and haemoglobin (r = −0.42, p < 0.01). A similar trend was observed for ischaemic heart disease history, however this was not statistically significant (p = 0.08). Conclusion: In stable high risk patients undergoing elective non-cardiac surgery, approximately one-quarter will have an elevated pre-operative hs-TnT. Factors associated with this include age, renal dysfunction, and anaemia. Given an elevated hs-TnT in stable populations is associated with worse cardiovascular outcomes, the impact on peri-operative morbidity and mortality merits further evaluation. doi:10.1016/j.hlc.2011.05.520 517 Pre-operative Kidney Function as a Predictor of Adverse Outcomes after Surgery—A Systematic Review and Metaanalysis J. Mooney 1,∗ , I. Ranasinghe 1 , C. Chow 1,2 , F. Barzi 1 , S. Zoungas 1,3 , T. Tan 2 , V. Perkovic 1 , G. Hillis 1 1 The
George Institute for Global Health, Sydney, Australia Hospital, Sydney, Australia 3 Monash University, Melbourne, Australia 2 Westmead
Background: Creatinine levels predict adverse outcomes after surgery but are an imprecise measure of kidney function, and estimated glomerular filtration rate (eGFR) could have greater predictive value. This study assessed the strength of the relationship between eGFR and postoperative outcomes. Method: A systematic review and meta-analysis were undertaken. Cohort studies were included if they reported the relationship between eGFR and outcomes including major adverse cardiovascular events (MACE), acute kidney injury (AKI) and all-cause mortality, in people having cardiac or non-cardiac surgery. Results: Forty-seven studies enrolling 681,065 patients were included. An eGFR < 60 mL/min per 1.73 m2 was associated with an increased risk of all-cause mortal-
Heart, Lung and Circulation 2011;20S:S156–S251
ity (relative risk [RR] 3.50, 95% confidence interval [CI] 2.19–5.59) and AKI (RR 3.09, 95% CI 2.06–4.82) at short term follow up (in hospital or 30 days). At final follow up, it was associated with an increased risk of MACE (RR 1.48 95% CI 1.32–1.67) and all-cause mortality (RR 1.78 95% CI 1.50–2.08). There was a significant inverse linear association between eGFR and risk. Each 10 mL/min per 1.73 m2 lower eGFR was associated with an increased risk of death (short-term RR 1.27 [1.23–1.31] and long-term 1.17 [1.12–1.22]). Conclusion: Kidney function defined using eGFR demonstrates a powerful inverse linear relationship to both short and long-term outcomes after surgery. Further work is required to assess whether eGFR provides prognostic information that improves existing risk prediction tools in this setting. doi:10.1016/j.hlc.2011.05.521 518 Prevalence of Known and Incidental Atrial Fibrillation in a Relatively Healthy Population Aged Over 40 Deif B 1,∗ , Freedman S 1,2,3,∗ 1 Concord
Clinical School, University of Sydney, Australia Research Institute, Australia 3 Dept. Cardiology Concord Hospital, Australia 2 ANZAC
Background: Atrial Fibrillation (AF) is the most common sustained arrhythmia, but is often unrecognised, with 22% of AF-related ischaemic stroke occurring in incidentally documented AF. We sought to determine the prevalence of known and incidental AF in an otherwise healthy population > 40 years old. Methods: Surgical pre-admissions ECGs, routinely performed in those >40, were scrutinised, and charts of those in AF reviewed. Results: Of 1024 pre-admission ECGs we found 32 (3.1%) showing AF. The mean age of those in AF was 79 ± 7. Medical records of 17/430 were available for review but the study is ongoing. Overall 2/17 (0.5%) were incidental and 15 (3.5%) were known to have AF. Incidental AF cases were similar in age to patients with known AF (78 and 77 vs 79 ± 7), and had high CHADS2 score (5 and 3 vs 2.3 ± 1.2 for known AF). Only 6/12 patients with known AF and CHADS2 score ≥2 were on warfarin. 10/15 with known AF were on rate control drugs (mean resting heart rate 85 ± 14/min). Neither patient with incidental AF experienced palpitations, and resting heart rate was 96 and 76 respectively. Conclusions: AF is prevalent in an otherwise well population > 40. Unrecognised AF found in 0.5%, was unassociated with symptoms, and resting heart rate was not elevated, even in the absence of therapy to control rate. Patients with incidental AF may have CHADS2 score high enough to warrant anti-coagulation, indicating an appreciable asymptomatic group who may benefit from recognition and thromboprophylaxis to reduce future stroke. doi:10.1016/j.hlc.2011.05.522
Abstracts
ABSTRACTS
stable coronary artery disease, and is significantly associated with adverse long-term cardiovascular outcomes. The aim of our study was to investigate baseline troponin (both 4th generation and hs-TnT) concentrations in high-risk patients undergoing elective non-cardiac surgery. Methods: Consecutive patients undergoing elective non-cardiac surgery, currently prescribed anti-platelet therapy because they were deemed high risk, were included. Patient demographics and comorbidities were collected. Baseline hs-TnT (Roche Diagnostics, ninetyninth percentile 13 ng/L, limit of detection 2 ng/L), and fourth generation TnT (Roche Diagnostics, 99th percentile 10 ng/L, limit of detection 10 ng/L) were collected in all patients. Results: One hundred and ten consecutive patients were recruited (mean age: 72 ± 9.7 years, 64% male). Hs-TnT concentration was elevated above the ninety-ninth percentile in 29 (26%) patients, with only seven (6%) elevated using the older fourth generation assay. Multivariate predictors of elevated hs-TnT included; age (r = 0.42, p < 0.01); estimated glomerular filtration rate (r = −0.67, p < 0.01); and haemoglobin (r = −0.42, p < 0.01). A similar trend was observed for ischaemic heart disease history, however this was not statistically significant (p = 0.08). Conclusion: In stable high risk patients undergoing elective non-cardiac surgery, approximately one-quarter will have an elevated pre-operative hs-TnT. Factors associated with this include age, renal dysfunction, and anaemia. Given an elevated hs-TnT in stable populations is associated with worse cardiovascular outcomes, the impact on peri-operative morbidity and mortality merits further evaluation. doi:10.1016/j.hlc.2011.05.520 517 Pre-operative Kidney Function as a Predictor of Adverse Outcomes after Surgery—A Systematic Review and Metaanalysis J. Mooney 1,∗ , I. Ranasinghe 1 , C. Chow 1,2 , F. Barzi 1 , S. Zoungas 1,3 , T. Tan 2 , V. Perkovic 1 , G. Hillis 1 1 The
George Institute for Global Health, Sydney, Australia Hospital, Sydney, Australia 3 Monash University, Melbourne, Australia 2 Westmead
Background: Creatinine levels predict adverse outcomes after surgery but are an imprecise measure of kidney function, and estimated glomerular filtration rate (eGFR) could have greater predictive value. This study assessed the strength of the relationship between eGFR and postoperative outcomes. Method: A systematic review and meta-analysis were undertaken. Cohort studies were included if they reported the relationship between eGFR and outcomes including major adverse cardiovascular events (MACE), acute kidney injury (AKI) and all-cause mortality, in people having cardiac or non-cardiac surgery. Results: Forty-seven studies enrolling 681,065 patients were included. An eGFR < 60 mL/min per 1.73 m2 was associated with an increased risk of all-cause mortal-
Heart, Lung and Circulation 2011;20S:S156–S251
ity (relative risk [RR] 3.50, 95% confidence interval [CI] 2.19–5.59) and AKI (RR 3.09, 95% CI 2.06–4.82) at short term follow up (in hospital or 30 days). At final follow up, it was associated with an increased risk of MACE (RR 1.48 95% CI 1.32–1.67) and all-cause mortality (RR 1.78 95% CI 1.50–2.08). There was a significant inverse linear association between eGFR and risk. Each 10 mL/min per 1.73 m2 lower eGFR was associated with an increased risk of death (short-term RR 1.27 [1.23–1.31] and long-term 1.17 [1.12–1.22]). Conclusion: Kidney function defined using eGFR demonstrates a powerful inverse linear relationship to both short and long-term outcomes after surgery. Further work is required to assess whether eGFR provides prognostic information that improves existing risk prediction tools in this setting. doi:10.1016/j.hlc.2011.05.521 518 Prevalence of Known and Incidental Atrial Fibrillation in a Relatively Healthy Population Aged Over 40 Deif B 1,∗ , Freedman S 1,2,3,∗ 1 Concord
Clinical School, University of Sydney, Australia Research Institute, Australia 3 Dept. Cardiology Concord Hospital, Australia 2 ANZAC
Background: Atrial Fibrillation (AF) is the most common sustained arrhythmia, but is often unrecognised, with 22% of AF-related ischaemic stroke occurring in incidentally documented AF. We sought to determine the prevalence of known and incidental AF in an otherwise healthy population > 40 years old. Methods: Surgical pre-admissions ECGs, routinely performed in those >40, were scrutinised, and charts of those in AF reviewed. Results: Of 1024 pre-admission ECGs we found 32 (3.1%) showing AF. The mean age of those in AF was 79 ± 7. Medical records of 17/430 were available for review but the study is ongoing. Overall 2/17 (0.5%) were incidental and 15 (3.5%) were known to have AF. Incidental AF cases were similar in age to patients with known AF (78 and 77 vs 79 ± 7), and had high CHADS2 score (5 and 3 vs 2.3 ± 1.2 for known AF). Only 6/12 patients with known AF and CHADS2 score ≥2 were on warfarin. 10/15 with known AF were on rate control drugs (mean resting heart rate 85 ± 14/min). Neither patient with incidental AF experienced palpitations, and resting heart rate was 96 and 76 respectively. Conclusions: AF is prevalent in an otherwise well population > 40. Unrecognised AF found in 0.5%, was unassociated with symptoms, and resting heart rate was not elevated, even in the absence of therapy to control rate. Patients with incidental AF may have CHADS2 score high enough to warrant anti-coagulation, indicating an appreciable asymptomatic group who may benefit from recognition and thromboprophylaxis to reduce future stroke. doi:10.1016/j.hlc.2011.05.522