Methods -We analysed 189 consecutive patients who underwent ablation for typical atrial flutter (AFL), in which the incidence of atrial flutter was the first manifestation of cardiac disease.
According to clinical standards of our center, the routine recommendation was to evaluate for CAD by invasive angiogram or CT-scan.
We compared the AFL patients to 141 patients with paroxysmal atrial fibrillation (AFIB) without known structural heart disease who underwent ablation in the same period and who had routine coronary angiograms performed.
Results - Out of 189 patients who presented with AFL, coronary status was available in 152 patients (80.4 %). Both groups were balanced for mean age (64.9 years in AFL vs. 63.2 years in AFIB; p=0.15), body-mass-index (BMI; 28.8 vs. 28.5 kg/m2; p=0.15), CHA2DS2-VASc-Score (2.20 vs. 2.04; p=0.35), smoking status (22.2 % smokers vs. 28.4 %; p=0.23) and renal function (GFR >60 ml/min in 96.7 % of all patients vs. 95.7 %; p=0.76). There were significantly lower values for left-ventricular ejection fraction (52.5 % vs. 59.7 %; p<0.001), female sex (17.0 % vs. 47.5 %; p<0.001), hyperlipidemia (37.9 % vs. 58.9 %; p<0.001) and family history of cardiovascular disease (15.0 vs. 31.9 %; p=0.001) in the AFL vs. AFIB cohorts.
CAD with stenoses >50 % was found in 26.3 % of all patients with available coronary status in AFL and in 7.0 % in AFIB (p<0.001). CAD with stenoses >75 % in 16.4 % in AFL whereas only in 1.4 % in AFIB (p<0.001). Multivessel disease was detected in 10.5 % in AFL and 0.7 % in AFIB (p<0.001).
After correction for age, LVEF, BMI, CHA2DS2-VASc-Score and it's individual components, smoking status, hyperlipidemia and family history of cardiovascular disease, there was a more than five-fold increase in the likelihood of CAD with stenosis >50 % in AFL as compared to AFIB (OR 5.26).
A multivariate analysis was performed in the AFL group. Patients with clinically relevant stenoses (>75 %) were older (70.6 years vs. 63.8 years; p=0.001), had a higher number of risk factors (3.08 vs. 2.24; p=<0.0016) and a higher CHA2DS2-VASc-Score (3.20 vs 2.00; p<0.0001). With logistic regression, significant CAD could be predicted by higher values for CHA2DS2-VASc-Score with an exponential rise to a pretest-probability of 42.1 % at a value of 4 points.
Discussion- This data suggests that typical atrial flutter constitutes a manifestation for previously asymptomatic CAD. Due to the inclusion criteria, CAD has to be considered silent and stable in most of the patients. Therefore, the presence of typical atrial flutter in formerly healthy patients should raise suspicion of otherwise silent CAD and initiate further investigations and risk-stratification with particular emphasis on the individual CHA2DS2-VASc-Scores.