Andreas Breithecker

Balloon pulmonary angioplasty for inoperable patients with chronic thromboembolic pulmonary hypertension: the initial German experience

Balloon pulmonary angioplasty (BPA) is an emerging treatment for patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). We report on a prospective series of 56 consecutive patients who underwent 266 BPA interventions (median, five per patient) at two German institutions. All patients underwent a comprehensive diagnostic work-up including right heart catheterisation at baseline and 24 weeks after their last intervention. BPA resulted in improvements in WHO functional class, 6 min walk distance (mean change, +33 m), right ventricular function and haemodynamics, including a decline in mean pulmonary artery pressure by 18% and in pulmonary vascular resistance by 26%. Procedure-related adverse events occurred in 9.4% of the interventions. The most common complications were related to pulmonary vascular injury and consecutive pulmonary bleeding. Most of these events were asymptomatic and self-limiting, but one patient died from pulmonary bleeding, resulting in a mortality rate of 1.8%. BPA resulted in haemodynamic and clinical improvements but was also associated with a considerable number of complications, including one fatal pulmonary bleeding. As the effects of BPA on survival are unknown, randomised controlled outcome trials comparing BPA with approved medical therapies in patients with inoperable CTEPH are required to allow for appropriate risk–benefit assessments. BPA improves haemodynamics and exercise capacity in patients with inoperable CTEPH but complications are not uncommon http://ow.ly/mMYY30b1rch

Combined pulmonary endarterectomy and balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension.

BACKGROUND Pulmonary endarterectomy (PEA) is a curative treatment option for more than 60% of patients with chronic thromboembolic pulmonary hypertension (CTEPH). For selected inoperable patients, interventional balloon pulmonary angioplasty (BPA) has recently been established in addition to medical treatment. This approach disrupts scar tissue occluding the pulmonary arteries, leading to an improvement in parenchymal perfusion. CTEPH is occasionally heterogeneous, with operable disease on one side but peripheral, inoperable changes on the contralateral side. Performing unilateral PEA (on the operable side only) in these patients may lead to a worse hemodynamic outcome and increased mortality compared with patients who that can be surgically corrected bilaterally. We sought to determine the feasibility, safety, and benefits of BPA applied to the contralateral lung in several patients with predominantly unilateral disease that was amenable to treatment by PEA. METHODS Standard unilateral PEA in deep hypothermic circulatory arrest was performed in 3 CTEPH patients with poor pulmonary hemodynamics, and inoperability of the contralateral pulmonary artery obstructions was confirmed. The inoperable side was treated by BPA. The intervention was performed during the rewarming phase of cardiopulmonary bypass. RESULTS A dramatic improvement in pulmonary hemodynamics, with a mean reduction in pulmonary vascular resistance of 842 dyne · sec/cm(5), was achieved in all patients. World Health Organization Functional Class was also significantly improved at the midterm follow-up. CONCLUSIONS The combination of surgical PEA and interventional BPA is a new treatment option for highly selected high-risk CTEPH patients. A multidisciplinary CTEPH expert team is a basic pre-requisite for this complex concept.

Puncture of the popliteal artery using a Doppler-equipped (SMART) needle in transpopliteal interventions

Abstract. The puncture of the popliteal artery for percutaneous intervention is usually performed under fluoroscopic guidance or with the assistance of percutaneous ultrasound to avoid accidental arteriovenous fistulas. We present our experience in 119 cases with the use of a Doppler ultrasound equipped Seldinger needle (SMART needle) for the detection and puncture of the popliteal artery. In 119 interventions in 103 patients, the puncture of the popliteal artery was performed with the SMART needle. The puncture was successful in 94.1% (112 of 119) of cases. Six (5.2%) complications occurred during puncture: four hematomas (no therapy required) and two arteriovenous fistulas (treated by manual compression solely). The subsequent 112 interventions in 103 patients [98 percutaneous transluminal angioplasty (PTA), 8 PTA with stent implantations, 4 PTA with thrombolysis, 2 thrombolyses] were technically successful in 79.5% (89 of 112). The SMART-needle-guided popliteal puncture showed to be safe, fast, and easy to perform, which allowed the use of this technique by radiologists in training. The rates of success and complications are comparable to reported results for other visualization techniques, whereas time, effort, and training required are lower. This may contribute to a more widespread use of the transpopliteal access for interventions and therefore offers a therapeutic option in addition to vascular surgery.

3D imaging of lung tissue by confocal microscopy and micro-CT

Two complementary techniques for the imaging of tissue subunits are discussed. A computer guided light microscopic imaging technique is described first, which confocally resolves thick serial sections axially. The lateral area of interest is increased by scanning a mosaic of images in each plane. Subsequently, all images are fused digitally to form a highly resolved volume exhibiting the fine structure of complete respiratory units of lung. A different technique described is based on microtomography. This method allows to image volumes up to 3x3x3 cm at a resolution of up to 7 microns. Due to the lack of strong density differences, a contrast enhancement procedure is introduced which makes this technique applicable for the imaging of lung tissue. Imaging, visualization and analysis described here are parts of an ongoing project to model structure and to simulate function of tissue subunits and complete organs.

N-terminal pro–B-type natriuretic peptide for monitoring after balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension

BACKGROUND Balloon pulmonary angioplasty (BPA) is an emerging interventional treatment option for chronic thromboembolic pulmonary hypertension (CTEPH). The non-invasive monitoring of CTEPH patients is a clinical challenge. In this study we examined changes in N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients undergoing BPA for inoperable CTEPH and related them to peri-procedural success. METHODS In this study we analyzed a total of 51 consecutive patients who underwent BPA treatment and completed a 6-month follow-up (6-MFU) between March 2014 and March 2017. Serum samples for NT-proBNP measurement were collected before every BPA and at 6-MFU. RESULTS The 51 patients underwent 265 interventions involving angioplasty of a total of 410 vessels. The 6-month survival rate was 96.1%. The baseline (BL) mean pulmonary artery pressure (PAP) was 39.5 ± 12.1 mm Hg, pulmonary vascular resistance (PVR) was 515.8 ± 219.2 dynes/s/cm5 and the median NT-proBNP level was 820 (153 to 1,871.5) ng/liter. At BL, World Health Organization functional class (FC) was ≥III in 96.1% of the patients, whereas, at 6-MFU, 11.8% were in WHO FC ≥III. At 6-MFU, mean PAP (32.6 ± 12.6 mm Hg; p < 0.001), PVR (396.9 ± 182.6 dynes/s/cm5; p < 0.001) and NT-proBNP (159.3 [84.4 to 464.3] ng/liter; p < 0.001) levels were reduced. The decrease in NT-proBNP levels correlated with the decrease in mean PAP (rrs = 0.43, p = 0.002) and PVR (rrs = 0.50, p = 0.001). A reduction in the NT-proBNP level of 46% indicated a decrease in mean PAP of ≥25% (area under the curve [AUC] = 0.71) and a reduction of 61% indicated a decrease in PVR of ≥35% (AUC 0.77). CONCLUSIONS Our results demonstrate that NT-proBNP levels decrease after BPA, providing valuable evidence of procedural success. NT-proBNP measurement allows identification of patients who are BPA non-responders and may thus be a valuable adjunct in therapy monitoring.

Balloon pulmonary angioplasty for inoperable patients with chronic thromboembolic disease

Symptomatic patients with residual pulmonary perfusion defects or vascular lesions but no pulmonary hypertension at rest are diagnosed with chronic thromboembolic disease (CTED). Balloon pulmonary angioplasty (BPA) is an emerging treatment for patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH), but data regarding the safety and efficacy of BPA in patients with CTED are lacking. We report a prospective series of ten consecutive patients with CTED who underwent 35 BPA interventions (median of four per patient) at two German institutions. All patients underwent a comprehensive diagnostic workup at baseline and 24 weeks after their last intervention. BPA was safe, with one pulmonary vascular injury and subsequent self-limiting pulmonary bleeding as the only complication (2.9% of the interventions, 10% of the patients). After the procedures, World Health Organization functional class, 6-min walking distance, pulmonary vascular resistance, and pulmonary arterial compliance improved, and NT-proBNP concentrations declined in 9/10 patients. BPA may be a new treatment option for carefully selected patients with CTED. A larger, prospective, international registry is required to confirm these results.

Sequential treatment with riociguat and balloon pulmonary angioplasty for patients with inoperable chronic thromboembolic pulmonary hypertension

Riociguat is the treatment of choice for inoperable patients with chronic thromboembolic pulmonary hypertension (CTEPH). We addressed here whether additional balloon pulmonary angioplasty (BPA) provides further benefits. A prospective series of 36 consecutive patients with inoperable CTEPH were treated with riociguat at least three months before BPA. All patients underwent diagnostic workup at baseline, before BPA treatments, and six months after final intervention. The main outcome measures were pulmonary hemodynamic parameters and World Health Organization (WHO) functional class (FC). Significant improvements in pulmonary hemodynamics and physical capacity were observed for riociguat treatment, and subsequent BPA interventions yielded further benefits. With targeted medication, WHO FC improved by at least one class in 13 (36.1%) patients (P = 0.01). Hemodynamic assessment showed significant improvements in mean pulmonary arterial pressure (mPAP) (49 ± 12 mmHg vs. 43 ± 12 mmHg; P = 0.003) and PVR (956 ± 501 dyn·s·cm–5 vs. 517 ± 279 dyn·s·cm–5; P = 0.0001). Treatment with a combination of targeted medication and BPA resulted in WHO FC improvement in 34 (94.4%) patients. Hemodynamic assessment showed significant improvement in mPAP (43 ± 12 mmHg vs. 34 ± 14 mmHg; P = 0.0001) and PVR (517 ± 279 dyn·s·cm–5 vs. 360 ± 175 dyn·s·cm–5; P = 0.0001). These findings provide, for the first time, support for the therapeutic strategy recommended by current guidelines.

Dynamics of high-sensitivity cardiac troponin T during therapy with balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension

Aims Balloon pulmonary angioplasty (BPA) is an interventional treatment modality for inoperable chronic thromboembolic pulmonary hypertension (CTEPH). Therapy monitoring, based on non-invasive biomarkers, is a clinical challenge. This post-hoc study aimed to assess dynamics of high-sensitivity cardiac troponin T (hs-cTnT) as a marker for myocardial damage and its relation to N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels as a marker for cardiac wall stress. Methods and results This study included 51 consecutive patients who underwent BPA treatment and completed a 6-month follow-up (6-MFU) between 3/2014 and 3/2017. Biomarker measurement was performed consecutively prior to each BPA and at 6-MFU. In total, the 51 patients underwent an average of 5 BPA procedures. The 6-month survival rate was 96.1%. The baseline (BL) meanPAP (39.5±12.1mmHg) and PVR (515.8±219.2dyn×sec×cm-5) decreased significantly within the 6-MFU (meanPAP: 32.6±12.6mmHg, P<0.001; PVR: 396.9±182.6dyn×sec×cm-5, P<0.001). At BL, the median hs-cTnT level was 11 (IQR 6–16) ng/L and the median NT-proBNP level was 820 (IQR 153–1872) ng/L. The levels of both biomarkers decreased steadily after every BPA, showing the first significant difference after the first procedure. Within the 6-MFU, hs-cTnT levels (7 [IQR 5–12] ng/L; P<0.001) and NT-proBNP levels (159 [IQR 84–464] ng/l; P<0.001) continued to decrease. The hs-cTnT levels correlated with the PVR (rrs = 0.42; p = 0.005), the meanPAP (rrs = 0.32; p = 0.029) and the NT-proBNP (rrs = 0.51; p<0.001) levels at BL. Conclusion Non-invasive biomarker measurement provides valuable evidence for the decreasing impairment of myocardial function and structure during BPA therapy. Changes in hs-cTNT levels are suggestive for a reduction in ongoing myocardial damage.

Correlation of native T1 mapping with right ventricular function and pulmonary haemodynamics in patients with chronic thromboembolic pulmonary hypertension before and after balloon pulmonary angioplasty

ObjectivesThe aim of this study was to assess native T1 mapping in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) before and 6 months after balloon pulmonary angioplasty (BPA) and compare the results with right heart function and pulmonary haemodynamics.MethodsMagnetic resonance imaging at 1.5 T and right heart catheterisation were performed in 21 consecutive inoperable CTEPH patients before and 6 months after BPA. T1 values were measured within the septal myocardium, the upper and lower right ventricular insertion points, and the lateral wall at the basal short-axis section. In addition, the area-adjusted septal native T1 time (AA-T1) was calculated and compared with right ventricular function (RVEF), mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR).ResultsThe mean AA-T1 value decreased significantly after BPA (1,045.8 ± 44.3 ms to 1,012.5 ± 50.4 ms; p < 0.001). Before BPA, native T1 values showed a moderate negative correlation with RVEF (r = -0.61; p = 0.0036) and moderate positive correlations with mPAP (r = 0.59; p < 0.01) and PVR (r = 0.53; p < 0.05); after BPA correlation trends were present (r = -0.21, r = 0.30 and r = 0.35, respectively).ConclusionsNative T1 values in patients with inoperable CTEPH were significantly lower after BPA and showed significant correlations with RVEF and pulmonary haemodynamics before BPA. Native T1 mapping seems to be indicative of reverse myocardial tissue remodelling after BPA and might therefore have good potential for pre-procedural patient selection, non-invasive therapy monitoring and establishing a prognosis.Key Points• BPA is a promising treatment option for patients with inoperable CTEPH• Native septal T1 values significantly decrease after BPA and show good correlations with right ventricular function and haemodynamics before BPA• Prognosis and non-invasive therapy monitoring might be supported in the future by native T1 mapping