1Herz- und Diabeteszentrum NRW Allgemeine und Interventionelle Kardiologie/Angiologie Bad Oeynhausen, Deutschland; 2Herz- und Diabeteszentrum NRW Klinik für Thorax- und Kardiovaskularchirurgie Bad Oeynhausen, Deutschland; 3Herz- und Diabeteszentrum NRW Institut für Anästhesiologie und Schmerztherapie Bad Oeynhausen, Deutschland
Aims: The aim of this prospective study was to examine the hemodynamic effect of TAVI on the acute reduction in afterload in patients with severe aortic valve stenosis and different myocardial adaptation states of the left ventricle immediately and within the first 12 hours after the procedure.
Methods: Using the Acumen IQ sensor from Edwards Lifesciences which was connected to the arterial line pre-interventionally, pressure and volume changes were continuously monitored before and up to 12 hours after TAVI with the parameters stroke volume index (SVI), cardiac index (CI) and contractility (dP/dt) being measured every 20 seconds. Before the intervention, the left ventricular myocardial adaptation state was assessed by transthoracic echocardiography (TTE) and NT-proBNP levels.
Results: Patients were divided into five groups based on their left ventricular ejection fraction (EF) and NT-proBNP levels.
|
Group 1 - 5 |
n |
dP/dt pre [mmHg/s] |
dP/dt post1 [mmHg/s] |
dP/dt post2 [mmHg/s] |
p-value (pre -> post2)
|
|
(1) NT-proBNP < 450 pg/ml and EF ≥ 55% |
5 |
982 ± 395 |
953 ± 317 |
1.348 ± 250 |
0.077 |
|
(2) NT-proBNP > 450 to < 900/1800 pg/ml and EF ≥ 55% |
13 |
953 ± 290 |
888 ± 290 |
1.284 ± 241 |
0.002 |
|
(3) NT-proBNP > 900/ 1800 pg/ml and EF ≥ 55% |
11 |
957 ± 370 |
873 ± 263 |
1.173 ± 374 |
0.07 |
|
(4) NT-proBNP > 450 to 900/1.800 pg/ml and EF < 55% |
1 |
658 |
632 |
1.453 |
NT |
|
(5) NT-proBNP > 900/ 1.800 pg/ml and EF < 55% |
11 |
791 ± 343 |
831 ± 285 |
1.054 ± 382 |
0.007 |
|
Table 1: results for dP/dt pre: before TAVI; post1: immediately after aortic valve implantation; post2: 4 to 12h after TAVI | |||||
The table shows that acute afterload reduction after 4 to 12 hours led to a noticeable improvement in dP/dt in all patient groups and to a significant improvement of contractility in patients of group 2 and 5.
In contrast, there was no significant improvement of SVI in any patient group.
However, we observed a significant improvement of CI in patients with preserved systolic and slightly impaired diastolic left ventricular function (on average in group 2: pre-interventionally: 2.5 L/min/m2, after 4 to 12 hours: 2.8 L/min/m2, p=0.049; on average in Group 3: pre-interventionally: 2.3 L/min/m2, after 4 to 12 hours: 2.7 L/min/m2, p=0.015).
The significant improvements in dP/dt and CI were not observed immediately after aortic valve implantation but rather after 4 to 12 hours.
Conclusion: Patients with normal systolic and non-relevant diastolic dysfunction (group 1) have the best contractility data 4 to 12 hours after TAVI. Our data also show that the treatment of aortic stenosis is associated with the best hemodynamic results if it is performed before myocardial dysfunction has developed. Nevertheless, patients with already impaired myocardial adaption also benefit hemodynamically early after TAVI.