Atualização no Tratamento da Hipertensão Arterial Pulmonar / Update on the Treatment of Pulmonary Arterial Hypertension

Resumo Muitos avanços ocorreram nas últimas décadas na terapêutica da hipertensão arterial pulmonar (HAP), uma doença grave, progressiva, incurável e potencialmente fatal. Para seu tratamento adequado, são fundamentais o diagnóstico hemodinâmico e a classificação de sua etiologia, em que várias delas (colagenoses, hipertensão portal, cardiopatia congênitas, esquistossomose) requerem medidas específicas, além do tratamento farmacológico característico para HAP. O tratamento com fármacos-alvo para HAP baseia-se em produtos farmacêuticos que interferem em três vias fisiopatológicas moleculares: da prostaciclina, da endotelina e do óxido nítrico. Tais fármacos apresentam múltiplas apresentações (oral, endovenosa, subcutânea e inalatória) e mudaram a história da HAP. Essas medicações e suas estratégias de uso, assim como particularidades das diferentes formas de HAP, são o foco desta revisão.

Abstract In the last decades, important advances have been made in the treatment of pulmonary arterial hypertension (PAH), a severe, progressive, incurable, and potentially fatal disease. For an adequate therapy, correct hemodynamic diagnosis and etiology classification are fundamental. Many etiologies - rheumatic disease, portal hypertension, congenital heart diseases, schistosomiasis - require specific measures, in addition to drug therapy for PAH. The specific therapy for PAH is based on medications that act on three pathophysiological pathways - prostacyclin, endothelin, and nitric oxide pathways. These drugs have multiple presentations (oral, intravenous, subcutaneous, and inhaled) and have changed the history of PAH. This review presents an overview of drug therapy strategies and different forms and peculiarities of PAH.

Update on the Treatment of Pulmonary Arterial Hypertension. / Atualização no Tratamento da Hipertensão Arterial Pulmonar.

In the last decades, important advances have been made in the treatment of pulmonary arterial hypertension (PAH), a severe, progressive, incurable, and potentially fatal disease. For an adequate therapy, correct hemodynamic diagnosis and etiology classification are fundamental. Many etiologies - rheumatic disease, portal hypertension, congenital heart diseases, schistosomiasis - require specific measures, in addition to drug therapy for PAH. The specific therapy for PAH is based on medications that act on three pathophysiological pathways - prostacyclin, endothelin, and nitric oxide pathways. These drugs have multiple presentations (oral, intravenous, subcutaneous, and inhaled) and have changed the history of PAH. This review presents an overview of drug therapy strategies and different forms and peculiarities of PAH.

Muitos avanços ocorreram nas últimas décadas na terapêutica da hipertensão arterial pulmonar (HAP), uma doença grave, progressiva, incurável e potencialmente fatal. Para seu tratamento adequado, são fundamentais o diagnóstico hemodinâmico e a classificação de sua etiologia, em que várias delas (colagenoses, hipertensão portal, cardiopatia congênitas, esquistossomose) requerem medidas específicas, além do tratamento farmacológico característico para HAP. O tratamento com fármacos-alvo para HAP baseia-se em produtos farmacêuticos que interferem em três vias fisiopatológicas moleculares: da prostaciclina, da endotelina e do óxido nítrico. Tais fármacos apresentam múltiplas apresentações (oral, endovenosa, subcutânea e inalatória) e mudaram a história da HAP. Essas medicações e suas estratégias de uso, assim como particularidades das diferentes formas de HAP, são o foco desta revisão.

Electrical impedance tomography in pulmonary arterial hypertension.

The characterization of pulmonary arterial hypertension (PAH) relies mainly on right heart catheterization (RHC). Electrical impedance tomography (EIT) provides a non-invasive estimation of lung perfusion that could complement the hemodynamic information from RHC. To assess the association between impedance variation of lung perfusion (ΔZQ) and hemodynamic profile, severity, and prognosis, suspected of PAH or worsening PAH patients were submitted simultaneously to RHC and EIT. Measurements of ΔZQ were obtained. Based on the results of the RHC, 35 patients composed the PAH group, and eight patients, the normopressoric (NP) group. PAH patients showed a significantly reduced ΔZQ compared to the NP group. There was a significant correlation between ΔZQ and hemodynamic parameters, particularly with stroke volume (SV) (r = 0.76; P < 0.001). At 60 months, 15 patients died (43%) and 1 received lung transplantation; at baseline they had worse hemodynamics, and reduced ΔZQ when compared to survivors. Patients with low ΔZQ (≤154.6%.Kg) presented significantly worse survival (P = 0.033). ΔZQ is associated with hemodynamic status of PAH patients, with disease severity and survival, demonstrating EIT as a promising tool for monitoring patients with pulmonary vascular disease.

Use of medical therapies before pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension patients with severe hemodynamic impairment.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism, characterized by non-resolving fibro-thrombotic obstructions of large pulmonary arteries. Pulmonary endarterectomy (PEA) is the treatment of choice for the disease, significantly improving survival. Patients with worse hemodynamic profile have worse prognosis after surgery, raising the question of whether the use of medical therapy prior to surgery to optimize hemodynamics could improve outcomes. The aim of this study was to evaluate the role of medical therapy pre-PEA, according to the hemodynamic profile at the diagnosis. We retrospectively analyzed all patients submitted to PEA, from January 2013 to December 2017. Functional, clinical and hemodynamic data were collected to evaluate the main prognostic determinants. Patients were stratified according to the hemodynamic severity and use of targeted therapies prior to surgery. A total of 108 patients were included. Thirty-five patients (32,4%) used targeted therapy pre-PEA. The use of medical therapy delayed the surgical procedure by about 7 months. There was no difference in overall survival between patients that received targeted therapy and those treated only with supportive therapy (87.8% vs 80.3%, respectively, p = 0.426). Nevertheless, when analyzing the group of patients with severe hemodynamic impairment, defined by low cardiac output(<3.7L/min) at baseline, patients treated with targeted therapies presented a significantly better one-year survival. In higher-risk CTEPH patients, characterized by the presence of low cardiac output, the use of targeted therapies prior to PEA was associated with better outcome, suggesting a potential role for pre-operative use of medical treatment in this particular subgroup.

Lung Cavities in Chronic Thromboembolic Pulmonary Hypertension.

OBJECTIVES: Chronic thromboembolic pulmonary hypertension (CTEPH) is a unique form of pulmonary hypertension (PH) that arises from obstruction of the pulmonary vessels by recanalized thromboembolic material. CTEPH has a wide range of radiologic presentations. Commonly, it presents as main pulmonary artery enlargement, peripheral vascular obstructions, bronchial artery dilations, and mosaic attenuation patterns. Nevertheless, other uncommon presentations have been described, such as lung cavities. These lesions may be solely related to chronic lung parenchyma ischemia but may also be a consequence of concomitant chronic infectious conditions. The objective of this study was to evaluate the different etiologies that cause lung cavities in CTEPH patients. METHODS: A retrospective data analysis of the medical records of CTEPH patients in a single reference PH center that contained or mentioned lung cavities was conducted between 2013 and 2016. RESULTS: Seven CTEPH patients with lung cavities were identified. The cavities had different sizes, locations, and wall thicknesses. In two patients, the cavities were attributed to pulmonary infarction; in 5 patients, an infectious etiology was identified. CONCLUSION: Despite the possibility of being solely associated with chronic lung parenchyma ischemia, most cases of lung cavities in CTEPH patients were associated with chronic granulomatous diseases, reinforcing the need for active investigation of infectious agents in this setting.

Lung cavities in chronic thromboembolic pulmonary hypertension

OBJECTIVES: Chronic thromboembolic pulmonary hypertension (CTEPH) is a unique form of pulmonary hypertension (PH) that arises from obstruction of the pulmonary vessels by recanalized thromboembolic material. CTEPH has a wide range of radiologic presentations. Commonly, it presents as main pulmonary artery enlargement, peripheral vascular obstructions, bronchial artery dilations, and mosaic attenuation patterns. Nevertheless, other uncommon presentations have been described, such as lung cavities. These lesions may be solely related to chronic lung parenchyma ischemia but may also be a consequence of concomitant chronic infectious conditions. The objective of this study was to evaluate the different etiologies that cause lung cavities in CTEPH patients. METHODS: A retrospective data analysis of the medical records of CTEPH patients in a single reference PH center that contained or mentioned lung cavities was conducted between 2013 and 2016. RESULTS: Seven CTEPH patients with lung cavities were identified. The cavities had different sizes, locations, and wall thicknesses. In two patients, the cavities were attributed to pulmonary infarction; in 5 patients, an infectious etiology was identified. CONCLUSION: Despite the possibility of being solely associated with chronic lung parenchyma ischemia, most cases of lung cavities in CTEPH patients were associated with chronic granulomatous diseases, reinforcing the need for active investigation of infectious agents in this setting.

Extended anticoagulation after venous thromboembolism: should it be done?

Most physicians understand venous thromboembolism (VTE) to be an acute and time-limited disease. However, pathophysiological and epidemiological data suggest that in most patients VTE recurrence risk is not resolved after the first 6 months of anticoagulation. Recurrence rates are high and potentially life-threatening. In these cases, it would make sense to prolong anticoagulation for an undetermined length of time. However, what about the bleeding rates, induced by prolonged anticoagulation? Would they not outweigh the benefit of reducing the VTE recurrent risk? How long should anticoagulation be continued, and should all patients suffering from VTE be provided with extended anticoagulation? This review will address the most recent data concerning extended anticoagulation in VTE secondary prophylaxis. The reviews of this paper are available via the supplementary material section.

Use of direct oral anticoagulants for chronic thromboembolic pulmonary hypertension.

OBJECTIVES: Chronic thromboembolic pulmonary hypertension is one of the most prevalent forms of pulmonary hypertension and is a major complication of acute pulmonary embolism. One mainstay of chronic thromboembolic pulmonary hypertension treatment is lifelong anticoagulation. The recent advent of direct oral anticoagulants for acute pulmonary embolism treatment has provided a viable and effective alternative for treating this condition. However, little is known about the efficacy of this new class of drugs for treating chronic thromboembolic pulmonary hypertension. We aimed to evaluate the safety and efficacy of direct oral anticoagulants in the treatment of chronic thromboembolic pulmonary hypertension. METHODS: A cohort of chronic thromboembolic pulmonary hypertension patients who initiated treatment with direct oral anticoagulants between June 2015 and November 2016 were enrolled in this study. RESULTS: Sixteen patients used rivaroxaban, three used dabigatran and one used apixaban for a mean follow-up of 20.9 months. The mean age was 51 years, and eighteen patients were classified as functional class II/III. Eight patients underwent a pulmonary endarterectomy and exhibited clinical, hemodynamic and functional improvement and currently continue to use direct oral anticoagulants. No episode of venous thromboembolism recurrence was identified during the follow-up period, but there was one episode of major bleeding after a traumatic fall. CONCLUSIONS: Although direct oral anticoagulants appear to be a safe and effective alternative for treating chronic thromboembolic pulmonary hypertension, larger studies are needed to support their routine use.

RV Fractional Area Change and TAPSE as Predictors of Severe Right Ventricular Dysfunction in Pulmonary Hypertension: A CMR Study.

BACKGROUND: The right ventricular ejection fraction (RVEF) is a surrogate marker of right ventricular function in pulmonary hypertension (PH), but its measurement is complicated and time consuming. The tricuspid annular plane systolic excursion (TAPSE) measures only the longitudinal component of RV contraction while the right ventricular fractional area change (RVFAC) takes into account both the longitudinal and the transversal components. The aim of our study was to evaluate the relationship between RVEF, RVFAC, and TAPSE according to hemodynamic severity in two groups of patients with PH: pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). METHODS AND RESULTS: Fifty-four patients with PAH (n = 15) and CTEPH (n = 39) underwent right heart catheterization and cardiac magnetic resonance (CMR). The ventricular volumes and areas, TAPSE, and eccentricity index were measured. The RVFAC was more strongly correlated with the RVEF (r = 0.81, p < 0.0001) than the TAPSE (r = 0.63, p < 0.0001). RVEF < 35% was better predicted by the RVFAC than the TAPSE (TAPSE: AUC = 0.77 and RVFAC: AUC = 0.91; p = 0.042). In the group with the worse hemodynamic status, the RVFAC correlated much better with the RVEF than the TAPSE. There were no significant differences in the CMR data analyzed between the groups of PAH and CETPH patients. CONCLUSIONS: The RVFAC is a good index to estimate RVEF in PH patients; even better than the TAPSE in patients with more severe hemodynamic profile, possibly for including the transversal component of right ventricular function in its measurement. Furthermore, RVFAC performance was similar in the two PH groups (PAH and CTEPH).

Use of direct oral anticoagulants for chronic thromboembolic pulmonary hypertension

OBJECTIVES: Chronic thromboembolic pulmonary hypertension is one of the most prevalent forms of pulmonary hypertension and is a major complication of acute pulmonary embolism. One mainstay of chronic thromboembolic pulmonary hypertension treatment is lifelong anticoagulation. The recent advent of direct oral anticoagulants for acute pulmonary embolism treatment has provided a viable and effective alternative for treating this condition. However, little is known about the efficacy of this new class of drugs for treating chronic thromboembolic pulmonary hypertension. We aimed to evaluate the safety and efficacy of direct oral anticoagulants in the treatment of chronic thromboembolic pulmonary hypertension. METHODS: A cohort of chronic thromboembolic pulmonary hypertension patients who initiated treatment with direct oral anticoagulants between June 2015 and November 2016 were enrolled in this study. RESULTS: Sixteen patients used rivaroxaban, three used dabigatran and one used apixaban for a mean follow-up of 20.9 months. The mean age was 51 years, and eighteen patients were classified as functional class II/III. Eight patients underwent a pulmonary endarterectomy and exhibited clinical, hemodynamic and functional improvement and currently continue to use direct oral anticoagulants. No episode of venous thromboembolism recurrence was identified during the follow-up period, but there was one episode of major bleeding after a traumatic fall. CONCLUSIONS: Although direct oral anticoagulants appear to be a safe and effective alternative for treating chronic thromboembolic pulmonary hypertension, larger studies are needed to support their routine use.

Pulmonary artery enlargement in schistosomiasis associated pulmonary arterial hypertension.

BACKGROUND: Schistosomiasis associated pulmonary arterial hypertension (Sch-PAH) might represent the most prevalent form of PAH worldwide. In Sch-PAH, the presence of aneurismal dilation of the pulmonary artery has been described, although it is still a matter of debate whether on average the pulmonary artery is more enlarged in Sc-PAH than IPAH. METHODS: We retrospectively evaluated patients with IPAH (n = 25) and Sch-PAH (n = 22) who underwent computed tomography pulmonary angiogram and right heart catheterization. RESULTS: Sch-PAH patients were older and presented less severe hemodynamic profiles. Main pulmonary artery diameter (MPAD) was greater in Sch-PAH than IPAH (4.5 ± 1.8 vs 3.7 ± 1.1 cm, p = 0.018). For the same level of mean pulmonary artery pressure, the MPAD in Sch-PAH was 0.89 cm larger than in IPAH (Covariance model p = 0.02). CONCLUSION: This study demonstrated that pulmonary artery enlargement is more pronounced in Sch-PAH than IPAH, independently of mean pulmonary artery pressure level, suggesting that this is more likely a feature of Sch-PAH.

Usefulness of Cardiovascular Magnetic Resonance Indices to Rule In or Rule Out Precapillary Pulmonary Hypertension.

BACKGROUND: Various cardiovascular magnetic resonance (CMR) imaging indices are used to assess pulmonary hypertension (PH; mean pulmonary artery pressure ≥ 25 mm Hg). We compared the value of CMR indices to diagnose precapillary PH in treatment-naive patients evaluated for the first time for known or suspected pulmonary vascular disease. METHODS: Right heart catheterization and CMR were performed within 48 hours of each other in 85 consecutive subjects. The tricuspid annular plane systolic excursion, right ventricular (RV) fractional area change (RVFAC), RV ejection fraction, systolic eccentricity index, and RV end-diastolic area over left ventricular end-diastolic area ratio were calculated. The pulmonary artery trunk diameter, main pulmonary artery relative area change, and mean flow velocity were also calculated. RESULTS: There were 20 non-PH subjects (14 women/6 men, 55 ± 14 years of age, mean pulmonary artery pressure [mPAP] = 20 ± 4 mm Hg) and 65 precapillary PH subjects (32 women/33 men, 60 ± 15 years of age; P = not significant; mPAP = 46 ± 12 mm Hg; 54% with chronic thromboembolic PH). All CMR indices showed essentially the same (good) value to rule in precapillary PH. The RV end-diastolic area over left ventricular end-diastolic area ratio and RVFAC, which are relatively easy to measure, had a large area under the receiver operating characteristic curve (0.93, with optimal cut-off > 0.96, and 0.92, with optimal cut-off ≤ 35%, respectively), not significantly different from RV ejection fraction. In addition, RVFAC > 45% was documented in none of 65 PH and in 10 of 20 non-PH; thus, in a population similar to ours, RVFAC measurement could potentially have avoided unnecessary catheterization in 50% of non-PH subjects. CONCLUSIONS: In treatment-naive subjects in whom pulmonary vascular disease is highly suspected, right-sided CMR indices distinguish between PH and non-PH patients. RVFAC might have particular value in excluding precapillary PH.

Pulmonary arterial hypertension in the southern hemisphere: results from a registry of incident Brazilian cases.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a rare and ultimately fatal disorder of the pulmonary vasculature. There is increasing interest in the worldwide characteristics of patients with PAH, although data coming from the Southern Hemisphere remain scarce. The objective of this study was to describe a cohort of incident patients with PAH from a large reference center in Brazil. METHODS: All consecutive patients who received a diagnosis of PAH by right-sided heart catheterization between 2008 and 2013 were included in the study. RESULTS: A total of 178 patients with newly diagnosed PAH were enrolled in the study (mean age, 46 years; female/male ratio, 3.3:1; 45.5% in New York Heart Association functional class III or IV). Idiopathic PAH (IPAH), connective tissue disease (CTD), and schistosomiasis-associated PAH (Sch-PAH) accounted for 28.7%, 25.8%, and 19.7% of all cases, respectively. The patients were treated with phosphodiesterase type 5 inhibitors (66%), endothelin receptor antagonists (27%), or a combination of both (5%). For the PAH group as a whole, the estimated survival rate 3 years after diagnosis was 73.9%. The prognosis for the patients with CTD was worse than that for the patients with IPAH and Sch-PAH (P = .03). CONCLUSIONS: The distribution of PAH causes and the baseline characteristics in our registry clearly differ from the previously published European and US-based registries. These differences highlight the importance of regional registries and also raise questions regarding the need to better account for such differences in future clinical trials.

Left ventricular dysfunction in patients with suspected pulmonary arterial hypertension / Disfunção ventricular esquerda em pacientes com suspeita de hipertensão arterial pulmonar

OBJECTIVE: To evaluate the role of right heart catheterization in the diagnosis of pulmonary arterial hypertension (PAH). METHODS: We evaluated clinical, functional, and hemodynamic data from all patients who underwent right heart catheterization because of diagnostic suspicion of PAH-in the absence of severe left ventricular dysfunction (LVD), significant changes in pulmonary function tests, and ventilation/perfusion lung scintigraphy findings consistent with chronic pulmonary thromboembolism-between 2008 and 2013 at our facility. RESULTS: During the study period, 384 patients underwent diagnostic cardiac catheterization at our facility. Pulmonary hypertension (PH) was confirmed in 302 patients (78.6%). The mean age of those patients was 48.7 years. The patients without PH showed better hemodynamic profiles and lower levels of B-type natriuretic peptide. Nevertheless, 13.8% of the patients without PH were categorized as New York Heart Association functional class III or IV. Of the 218 patients who met the inclusion criteria, 40 (18.3%) and 178 (81.7%) were diagnosed with PH associated with LVD (PH-LVD) and with PAH, respectively. The patients in the HP-LVD group were significantly older than were those in the PAH group (p < 0.0001). CONCLUSIONS: The proportional difference between the PAH and PH-LVD groups was quite significant, considering the absence of echocardiographic signs suggestive of severe LVD during the pre-catheterization investigation. Our results highlight the fundamental role of cardiac catheterization in the diagnosis of PAH, especially in older patients, in whom the prevalence of LVD that has gone undiagnosed by non-invasive tests is particularly relevant. .

OBJETIVO: Avaliar o papel do cateterismo de câmaras cardíacas direitas no diagnóstico de hipertensão arterial pulmonar (HAP). MÉTODOS: Entre 2008 e 2013, foram avaliadas as características clínicas, funcionais e hemodinâmicas de todos os pacientes que realizaram cateterismo cardíaco direito por suspeita de HAP em nosso laboratório, depois de afastada a presença de disfunção ventricular esquerda (DVE) grave, de alterações significativas nos testes de função pulmonar ou de resultados de cintilografia pulmonar de inalação/perfusão compatíveis com tromboembolismo pulmonar crônico. RESULTADOS: Durante o período de estudo, 384 pacientes foram submetidos a cateterismo cardíaco diagnóstico. A hipertensão pulmonar (HP) foi confirmada em 302 pacientes (78,6%). A média de idade desses pacientes foi de 48,7 anos. Os pacientes sem HP apresentaram melhor perfil hemodinâmico e menores níveis de peptídio natriurético do tipo B que aqueles diagnosticados com HP. No entanto, 13,8% dos pacientes sem HP apresentavam-se em classe funcional III/IV do New York Heart Association. Dos 218 pacientes que cumpriam os critérios de inclusão, 40 (18,3%) e 178 (81,7%) foram diagnosticados como portadores de HP associada à DVE (HP-DVE) e HAP, respectivamente. O grupo HP-DVE tinha idade significativamente mais avançada que aqueles com HAP (p < 0,0001). CONCLUSÕES: A diferença proporcional entre os grupos HAP e HP-DVE foi bastante significativa, considerando a inexistência de sinais ecocardiográficos sugestivos de DVE importante como parte da investigação que antecedeu ...

Quality of life as a prognostic marker in pulmonary arterial hypertension.

BACKGROUND: Improvement in quality of life together with better survival are the ultimate goals in the treatment of pulmonary arterial hypertension (PAH) patients. The objective of this study was to evaluate the health-related quality of life (HRQL) of pulmonary arterial hypertension (PAH) patients with the SF-36 generic questionnaire and to identify the prognostic implication of this assessment. METHODS: Fifty-four consecutive newly diagnosed PAH patients (WHO classification group I) in a single PAH reference center were included. Patients were evaluated at baseline for clinical and hemodynamic parameters, and they subsequently received first-line therapy with either an endothelin receptor antagonist or a phosphodiesterase-5 inhibitor. After 16 weeks of specific PAH therapy, all patients were re-evaluated using a 6MWT and a SF 36 questionnaire, and then they were followed up for at least 36 months. RESULTS: After treatment, the patients demonstrated an improved 6MWT (414 ± 124 m vs. 440 ± 113 m, p = 0.001). Specific PAH therapy also improved the HRQL scores.Patients with a baseline Physical Component Score (PCS) higher than 32 had a better survival rate than those who had a score under 32 (p = 0.04). Similarly, patients with a PCS of at least a 38 after the 16 week therapy period had a better survival rate when compared with those who did not achieve this value (p = 0.016). Unlike the absolute PCS values, the post-treatment PCS variability was unable to predict better survival rates (p = 0.58). CONCLUSIONS: Our findings suggest that HRQL is associated with prognosis in PAH. Furthermore, achieving pre-determined PCS scores might represent a specific goal to be reached in treatment-to-target strategies.

Left ventricular dysfunction in patients with suspected pulmonary arterial hypertension.

OBJECTIVE: To evaluate the role of right heart catheterization in the diagnosis of pulmonary arterial hypertension (PAH). METHODS: We evaluated clinical, functional, and hemodynamic data from all patients who underwent right heart catheterization because of diagnostic suspicion of PAH--in the absence of severe left ventricular dysfunction (LVD), significant changes in pulmonary function tests, and ventilation/perfusion lung scintigraphy findings consistent with chronic pulmonary thromboembolism--between 2008 and 2013 at our facility. RESULTS: During the study period, 384 patients underwent diagnostic cardiac catheterization at our facility. Pulmonary hypertension (PH) was confirmed in 302 patients (78.6%). The mean age of those patients was 48.7 years. The patients without PH showed better hemodynamic profiles and lower levels of B-type natriuretic peptide. Nevertheless, 13.8% of the patients without PH were categorized as New York Heart Association functional class III or IV. Of the 218 patients who met the inclusion criteria, 40 (18.3%) and 178 (81.7%) were diagnosed with PH associated with LVD (PH-LVD) and with PAH, respectively. The patients in the HP-LVD group were significantly older than were those in the PAH group (p < 0.0001). CONCLUSIONS: The proportional difference between the PAH and PH-LVD groups was quite significant, considering the absence of echocardiographic signs suggestive of severe LVD during the pre-catheterization investigation. Our results highlight the fundamental role of cardiac catheterization in the diagnosis of PAH, especially in older patients, in whom the prevalence of LVD that has gone undiagnosed by non-invasive tests is particularly relevant.

OBJETIVO: Avaliar o papel do cateterismo de câmaras cardíacas direitas no diagnóstico de hipertensão arterial pulmonar (HAP). MÉTODOS: Entre 2008 e 2013, foram avaliadas as características clínicas, funcionais e hemodinâmicas de todos os pacientes que realizaram cateterismo cardíaco direito por suspeita de HAP em nosso laboratório, depois de afastada a presença de disfunção ventricular esquerda (DVE) grave, de alterações significativas nos testes de função pulmonar ou de resultados de cintilografia pulmonar de inalação/perfusão compatíveis com tromboembolismo pulmonar crônico. RESULTADOS: Durante o período de estudo, 384 pacientes foram submetidos a cateterismo cardíaco diagnóstico. A hipertensão pulmonar (HP) foi confirmada em 302 pacientes (78,6%). A média de idade desses pacientes foi de 48,7 anos. Os pacientes sem HP apresentaram melhor perfil hemodinâmico e menores níveis de peptídio natriurético do tipo B que aqueles diagnosticados com HP. No entanto, 13,8% dos pacientes sem HP apresentavam-se em classe funcional III/IV do New York Heart Association. Dos 218 pacientes que cumpriam os critérios de inclusão, 40 (18,3%) e 178 (81,7%) foram diagnosticados como portadores de HP associada à DVE (HP-DVE) e HAP, respectivamente. O grupo HP-DVE tinha idade significativamente mais avançada que aqueles com HAP (p < 0,0001). CONCLUSÕES: A diferença proporcional entre os grupos HAP e HP-DVE foi bastante significativa, considerando a inexistência de sinais ecocardiográficos sugestivos de DVE importante como parte da investigação que antecedeu o cateterismo. Nossos resultados reforçam o papel fundamental do cateterismo cardíaco no diagnóstico da HAP, ainda mais em faixas etárias mais avançadas, nas quais a prevalência de DVE não diagnosticada através de exames não invasivos é particularmente importante.

Strong linear relationship between heart rate and mean pulmonary artery pressure in exercising patients with severe precapillary pulmonary hypertension.

The contribution of heart rate (HR) to pulmonary artery hemodynamics has been suggested in pulmonary hypertension (PH). Our high-fidelity pressure, retrospective study tested the hypothesis that HR explained the majority of mean pulmonary artery pressure (mPAP) and pulse pressure (PApp) variation in 12 severe precapillary PH patients who performed incremental-load cycling while in the supine position. Seven idiopathic pulmonary arterial hypertension patients and five chronic thromboembolic PH patients were studied. Four to five PAP-thermodilution cardiac output (CO) points (mean: 4.4) were obtained. At rest, mPAP was 57 ± 9 mmHg, PApp was 51 ± 11 mmHg, HR was 90 ± 12 beats/min, and stroke volume (SV) was 50 ± 22 ml. At peak exercise, mPAP was 76 ± 10 mmHg, PApp was 67 ± 11 mmHg, and HR was 123 ± 18 beats/min (i.e., 71 ± 10% of maximum HR, each P < 0.05), whereas SV was 51 ± 20 ml (P = not significant). The input resistance did not change (mPAP/CO = 14.1 ± 4.1 vs. 13.5 ± 4.4 mmHg·min·l(-1)). The relative increase in mPAP was related to the relative increase in HR (n = 12, r(2) = 0.74) but not in CO. mPAP was linearly related to CO in 8 of 12 patients (median r(2) = 0.83) and to HR in 12 of 12 patients (median r(2) = 0.985). The parsimony principle favored the latter fit. PApp was linearly related to mPAP in 12 of 12 patients (median r(2) = 0.985), HR in 10 of 12 patients (median r(2) = 0.97), CO in 7 of 12 patients (median r(2) = 0.87), and SV in 1 of 12 patients. A strong linear relationship between HR and mPAP was consistently documented in severe precapillary PH patients who performed supine exercise. The limited value of thermodilution CO to predict mPAP could be explained by unavoidable precision errors in CO measurements, unchanged/decreased SV on exercise, curvilinearity of the mPAP-CO relationship at high flow, or flow-independent additional mechanisms increasing mPAP on exercise.

Estimating right ventricular stroke work and the pulsatile work fraction in pulmonary hypertension.

BACKGROUND: The mean pulmonary artery pressure (mPAP) replaces mean systolic ejection pressure (msePAP) in the classic formula of right ventricular stroke work (RVSW) = (mPAP - RAP) × stroke volume, where RAP is mean right atrial pressure. Only the steady work is thus taken into account, not the pulsatile work, whereas pulmonary circulation is highly pulsatile. Our retrospective, high-fidelity pressure study tested the hypothesis that msePAP was proportional to mPAP, and looked at the implications for RVSW. METHODS: Eleven patients with severe, precapillary pulmonary hypertension (PH) (six patients with idiopathic pulmonary arterial hypertension and five with chronic thromboembolic PH; mPAP = 57 ± 10 mm Hg) were studied at rest and during mild to moderate exercise. Eight non-PH control subjects were also studied at rest (mPAP = 16 ± 2 mm Hg). The msePAP was averaged from end diastole to dicrotic notch. RESULTS: In the full data set (53 pressure-flow points), mPAP ranged from 14 to 99.5 mm Hg, cardiac output from 2.38 to 11.1 L/min, and heart rate from 53 to 163 beats/min. There was a linear relationship between msePAP and mPAP (r² = 0.99). The msePAP matched 1.25 mPAP (bias, -0.5 ± 2.6 mm Hg). Results were similar in the resting non-PH group and in resting and the exercising PH group. This implies that the classic formula markedly underestimates RVSW and that the pulsatile work may be a variable 20% to 55% fraction of RVSW, depending on RAP and mPAP. At rest, RVSW in patients with PH was twice as high as that of the non-PH group (P < .05), but pulsatile work fraction was similar between the two groups (26 ± 4% vs 24 ± 1%) because of the counterbalancing effects of high RAP (11 ± 5 mm Hg vs 4 ± 2 mm Hg), which increases the fraction, and high mPAP, which decreases the fraction. CONCLUSIONS: Our study favored the use of an improved formula that takes into account the variable pulsatile work fraction: RVSW = (1.25 mPAP - RAP) × stroke volume. Increased RAP and increased mPAP have opposite effects on the pulsatile work fraction.