Authors: Alexander C Egbe, William R Miranda, C Charles Jain, Barry A Borlaug, Heidi M Connolly
Journal: Hypertension 2022; 79:2796-2805. Doi 10.1161/hypertensionAHA.122/19735
Take home points:
- 327 patients with repaired coarctation on antihypertensive therapy were evaluated by cardiopulmonary exercise testing
- Exercise induced hypertension (males > 210 mmHg, females > 190 mmHg) was present in 35% of these patients; 29% of those with optimal SBP had EIH
- Patients with EIH had higher effective arterial elastance index and lower total arterial compliance index and more advanced LV remodeling compared to those without EIH
- Exercise systolic BP was associated with adverse cardiovascular events (atrial fibrillation, non-sustained VT, sustained VT, heart failure hospitalization, or death) in 89 (27%) of patients independent of BP at rest. Those on intense anti-hypertensive therapy had less cardiovascular events
- Patients with EIH were less likely to be on ACEi /ARBs
- Patients on ACEi/ARBs reduce exercise induced SBP and these patients had lower risk of cardiovascular events
- Resting SBP (in clinic settings) does not predict EIH and ambulatory BP monitoring and exercise testing can be used for BP screening and improve antihypertensive therapy
Commentary from Dr. Thomas Zellers (Dallas, USA), section editor of Congenital Heart Disease Interventions and ACHD Journal Watch:
This is a retrospective study which included 327 patients with repaired coarctation who were treated with antihypertensives for more than a year who underwent cardiopulmonary exercise testing and have been followed for more than a year from the exercise testing. Patients with LV inflow disease, mitral regurgitation, persistent coarctation or aberrant right subclavian artery were excluded. Blood pressures at three intervals were measured and averaged. There was good correlation between the three readings. All exercised to maximal effort and exercise induced hypertension (EIH) was defined as a systolic blood pressure (SBP) > 210 mmHg for males and > 190 mmHg for females. Pulsatile arterial load was measured by echo and evaluated effective arterial elastance index (0.9 x brachial systolic BP/doppler derived stroke volume index) and total arterial compliance index (Doppler-derived stroke volume index/branchial pulse pressure). Incident cardiovascular events were defined as new onset atrial fibrillation, sustained or non-sustained VT, heart failure hospitalization or cardiovascular death.
The mean age at first evaluation was 35 +/- 13 years. See table 1 for baseline characteristics. Patients were followed for an average of 7.6 +/- 3.2 years.
Antihypertensive therapies used were ACEi/ARBs in 59%, betablockers in 51%, while 30% were on more than one medication and 27% had intensification of therapy during the follow up. Half of the patients were on optimal antihypertensive therapy at the start of the study with average SBP < 130 mmHg.
Exercise testing was performed in all patients with 35% having EIH. There was no correlation between resting systolic or diastolic blood pressure or pulse pressure and those metrics measured at exercise. There was also no difference in exercise BP in patients with simple vs complex coarctation (those with LV outflow disease like bicuspid aortic valve or supravalvar aortic stenosis). The group of patients with EIH also had a higher effective arterial elastance index and lower total arterial compliance index.
Eighty nine of 327 (27%) had at least one cardiovascular adverse event with 32 cardiovascular deaths. Patients with optimal resting SBP and those taking ACEi/ARBs had fewer adverse events.
Optimal SBP was found in 146 patients and 42 (29%) of those patients had EIH. The incidence of adverse events was higher in patients with EIH (hazard ratio 1.97) compared to those without EIH, independent of resting SBP, antihypertensive medications or echocardiographic indices. See Table 4. Patients with EIH who had intensification of antihypertensives, had fewer adverse events, suggesting that aggressive hypertension therapy, especially the use of ACEi/ARBs, reduces longer term adverse cardiovascular events.
The authors suggest that resting systolic BP is not an adequate indicator of who will develop hypertension after repaired coarctation. Exercise testing can unmask hypertension and help determine who needs aggressive and more aggressive antihypertensive therapy. It serves as a better screen than resting SBP. ACE inhibitors/ARBs were particularly protective and could help reduce exercise induced SBP. In addition, exercise SBP can be used to assess adequacy of antihypertensive therapy.
There were a number of limitations. It was retrospective, single center, and observational. There might have been selection and treatment biases as well. However, the statistical analysis does support the important conclusions and take-home points.
What does this mean for clinicians:
These data would support ambulatory BP monitoring and exercise testing even for patients with normal resting systolic BPs. There is a 29% incidence of EIH even in patients with optimally treated resting SBP. IF EIH is found, it is usually associated with a greater arterial load even with normal resting SBP and has a higher incidence of adverse cardiac events. EIH can be a trigger for more aggressive blood pressure treatment as ACEi/ARBs were associated with a reduced incidence of EIH and reduced incidence of adverse events. This suggests we should be more aggressive with our screening tools and with our treatment.