Effect of Balloon Pulmonary Angioplasty on Homogenization of Lung Perfusion Blood Volume by Dual-Energy Computed Tomography in Patients with Chronic Thromboembolic Pulmonary Hypertension.

OBJECTIVE: Balloon pulmonary angioplasty (BPA) is used to treat patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH); the goal is to improve pulmonary perfusion. We aimed to evaluate lung perfusion blood volume (PBV) with haemodynamic and exercise-capacity parameters to assess the efficacy of BPA in the treatment of CTEPH. METHODS: We retrospectively studied 33 patients over a 6-year period. DECT pulmonary angiography was performed before and after BPA. DECT provided iodine distribution maps; whole-lung and regional PBV images and quantification were generated using post-processing software. A mosaic pattern suggesting perfusion inhomogeneity is typical in CTEPH. Hypothetically, BPA treatment would promote homogenization that would be reflected in the calculated standard deviation. RESULTS: Lung perfusion images showed decreased heterogeneity after BPA. There was a significant difference before and after BPA in the whole-lung PBV and in the regional standard deviation for pulmonary arterial pressure (R = 0.37, p = 0.032 and R = 0.57, p = 0.006), pulmonary vascular resistance (R = 0.51, p = 0.023 and R = 0.60, p = 0.002), transtricuspid pressure gradient (R = 0.50, p = 0.0028 and R = 0.61, p = 0.0001), brain natriuretic peptide (R = 0.54, p = 0.0012 and R = 0.46, p = 0.0078), and 6-min walking distance (R = 0.59, p = 0.003 and R = 0.26, p = 0.14). The effects were especially pronounced after the first BPA procedure. CONCLUSION: Decreased lung heterogeneity may suggest BPA efficacy in treating CTEPH. After BPA treatment, improved lung PBV and improved regional standard deviation showed a strong positive correlation with haemodynamic parameters and exercise capacity, which also suggests that BPA is effective in treating CTEPH.

Comparative clinical and predictive value of lung perfusion blood volume CT, lung perfusion SPECT and catheter pulmonary angiography images in patients with chronic thromboembolic pulmonary hypertension before and after balloon pulmonary angioplasty.

OBJECTIVES: Lung perfusion blood volume (PBV) using dual-energy computed tomography has recently become an accepted technique for diagnosing pulmonary thromboembolism. We evaluated the correlation among lung PBV, single-photon emission computed tomography (SPECT) and catheter pulmonary angiography images in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after balloon pulmonary angioplasty (BPA). METHODS: In total, 17 patients and 57 sessions were evaluated with the three modalities. Segmental lung perfusion and its improvement in lung PBV and SPECT were compared with catheter pulmonary angiography as the reference standard before and after BPA. RESULTS: The sensitivity for detecting segmental perfusion defects using SPECT and lung PBV was 85% and 92%, the specificity was 99% and 99%, the accuracy was 92% and 95%, the positive predictive value was 99% and 99%, and the negative predictive value was 88% and 93%. The sensitivity for detecting segmental perfusion improvement using SPECT and lung PBV was 61% and 69%, the specificity was 75% and 83%, the accuracy was 62% and 70%, the positive predictive value was 97% and 98%, and the negative predictive value was 12% and 16%. CONCLUSIONS: Lung PBV is a useful technique for evaluation of segmental lung perfusion and its improvement in patients with CTEPH. KEY POINTS: • BPA is a new treatment for patients with CTEPH. • Lung PBV images may be more sensitive for pulmonary blood flow. • The current work demonstrates that Lung PBV images are useful in evaluating patients with CTEPH. • The current work demonstrates that Lung PBV is useful in gauging the treatment effect of BPA.

Correlation between lung perfusion blood volume and SPECT images in patients with chronic thromboembolic pulmonary hypertension by balloon pulmonary angioplasty.

OBJECTIVES: We evaluated the reperfusion by balloon pulmonary angioplasty (BPA) in lung PBV and SPECT images. METHODS: In total, 17 patients and 57 sessions were evaluated. Pre-BPA and post-BPA lung PBV and SPECT/CT images, based on both anatomical segments and physiologic regions (upper/middle/lower) were compared. RESULTS: BPA had a positive effect on most hypoperfused/unperfused segments/regions. There was generally a high rate of agreement between PBV measurements and SPECT/CT. CONCLUSIONS: BPA shows promise as a treatment modality for CTEPH patients. SPECT/CT, and, to a lesser extent, PBV, were useful in indicating areas in need of balloon angioplasty.

Quantification of lung perfusion blood volume (lung PBV) by dual-energy CT in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after balloon pulmonary angioplasty (BPA): Preliminary results.

OBJECTIVES: Balloon pulmonary angioplasty (BPA) is a treatment option for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Its effect on pulmonary perfusion has not been quantified; we examined the clinical significance of pulmonary blood volume (PBV) using dual-energy computed tomography (DECT) in patients with CTEPH undergoing BPA. METHODS: In this retrospective study of 16 BPAs in eight female patients with CTEPH, we evaluated both-lung (n=16), right- or left-lung (n=32), and three right- or left-segment (upper, middle, and lower) (n=96) PBVs before and after BPA, using DECT. We evaluated the relationships between improvement in lung PBV and pulmonary artery (PA) pressure (PAP), cardiac index (CI), pulmonary vascular resistance (PVR), and 6-min walking distance. We measured PA enhancement (PAenh) on DECT images and calculated lung PBV/PAenh to adjust timing. RESULTS: Pre- and post-BPA 6-segment lung PBV/PAenh were 0.067±0.021 and 0.077±0.019, respectively, in the treated segment (p<0.0001). There were significant positive correlations between pre- to post-BPA improvements in both-lung PBV/PAenh and PAP (R=0.69, p=0.005), PVR (R=0.56, p=0.03), and 6-min walking distance (R=0.67, p=0.01). CONCLUSIONS: Improved PBV after BPA, reflecting increased lung perfusion, was positively correlated with PAP, PVR, and 6-min walking distance. Lung PBV may be an indicator of BPA treatment effect.

Graves' disease complicated by ventricular fibrillation in three men who were smokers.

BACKGROUND: Thyrotoxicosis is known to be associated with sinus tachycardia and supraventricular tachyarrhythmias, but rarely with ventricular fibrillation (Vf), which has only occurred in some patients with hypokalemic periodic paralysis or ischemic heart disease. PATIENT FINDINGS: We present three men who were transferred to our hospital with Graves' disease who developed idiopathic Vf. None of them had hypokalemic periodic paralysis or ischemic heart disease but all were smokers. None of other patients with thyrotoxicosis (587 females and 155 males) who were seen at our hospital, in the period during which the three men were seen, had idiopathic Vf. In our three men with thyrotoxicosis and idiopathic Vf, there was no identifiable underlying heart disease. One of the three patients died of hypoxic encephalopathy. The other two men did not have recurrent Vf after their thyroid function normalized. SUMMARY: These cases and a review of similar cases in the literature imply that improving thyrotoxicosis seems to be effective for treating idiopathic Vf in some patients. CONCLUSIONS: Our findings suggest that thyroid hormone excess might play a direct role in the development of Vf in susceptible individuals. Our experience with these three patients suggests that smoking men with thyrotoxicosis likely have an increased risk for Vf, even if they do not have other predisposing factors.