Background:
Intraoperative hypotension (IOH) is commonly observed in patients undergoing surgical operations. Less is known about IOH during left atrial (LA) ablations, since these procedures were commonly performed with intermittent cuff measurements during analgo-sedation. Nowadays, innovative technologies supply non-invasively, reliable information regarding IOH in real-time. However, the effects of IOH regarding clinical outcomes in this patient population remain unclear.
Aim:
This study investigates the association of IOH and changes in laboratory values during LA ablations.
Methods:
Patients receiving LA ablation under deep analgesia-sedation with propofol, sufentanyl, and midazolam were included. A non-invasive continuous blood pressure monitoring was used during these procedures, and mean arterial pressure (MAP) measurements were calculated every 20 seconds. The response to IOH included volume substitution and administration of catecholamines. Information concerning the procedure and laboratory parameters (troponin (TNT), glomerular filtration rate (GFR)) before and 1 day after the procedure was provided. Three hypotensive groups are formed with thresholds of MAP 50 mmHg, 55 mmHg, and 60 mmHg. The difference of laboratory parameters (∆TNT = TNTafter – TNTbefore, ∆GRF = GRFafter - GFRbefore) was calculated for hypotensive and non-hypotensive groups. The burden of IOH was estimated using the area under the curve (AUC) for MAP < 55 mmHg throughout the procedure time.
Results:
The study cohort comprised 167 individuals, with 54% receiving pulsed field ablation (PFA), 43% radiofrequency ablation, and 3% cryoablation. Only 6% (10/167) of individuals experienced IOH with MAP < 50 mmHg. A significantly higher median ∆TNT release was documented in hypotensive versus non-hypotensive group for MAP threshold 50 mmHg (MAP < 50mmHg: median∆TNT 13167 ng/l, Interquartile Range (IQR) [7573, 15700], MAP > 50 mmgHg: median∆TNT TNT 3042 ng/l, IQR [885, 6062], p-value 0.007). The 18% (30/167) of participants experienced IOH with MAP < 55 mmHg had also a significantly higher ∆TNT compared to the non-hypotensive group (MAP < 55 mmHg: median∆TNT 2680 ng/l, IQR [874, 5900], MAP > 55 mmHg: median∆TNT 13167 ng/l, IQR [7573, 15700], p-value 0.004). The ∆TNT appeared to be non-statistically significant in 69 hypotensive patients when a MAP threshold of 60 mmHg was applied (p-value = 0.194).
Within the PFA group, the median number of additional energy applications (EA) was 4 (with IQR [2, 5]). The ∆TNT was not correlated with the number of additional EA (rho = - 0.07, p-value < 0.6). A weak positive association was detected between higher AUC for MAP < 55 mmHg and additional EA-number (rho = 0.2, p = 0.06). Reduced GFR was found in the group with MAP < 50 mmHg (MAP < 50 mmHg: median∆GRF -6.1 ml/min/1,73qm, IQR [-9.5, 0], MAP > 50 mmHg: median∆GRF 0 ml/min/1,73qm, IQR [-2.4, 0], p-value 0.13), but not in groups with MAP < 55 mmHg (p = 0.25) or < 60 mmHg (p = 0.25).
Conclusion:
In this study, the IOH was associated with higher TNT release and deterioration of kidney function for a MAP < 50 mmHg during LA ablation.
