Residual pulmonary vasodilative reserve predicts outcome in idiopathic pulmonary hypertension

Objective: Idiopathic pulmonary arterial hypertension (IPAH) remains a devastating and incurable, albeit treatable condition. Treatment response is not uniform and parameters that help to anticipate a rather benign or a malignant course of the disease are warranted. Acute pulmonary vasoreactivity testing during right heart catheterisation is recommended to identify a minority of patients with IPAH with sustained response to calcium channel blocker therapy. This study aimed to evaluate the prognostic significance of a residual pulmonary vasodilative reserve in patients with IPAH not meeting current vasoresponder criteria. Design: Observational right heart catheter study in 66 (n=66) patients with IPAH not meeting current vasoresponse criteria. Pulmonary vasodilative reserve was assessed by inhalation of 5 µg iloprost-aerosol. Results: Sixty-six (n=66) of 72 (n=72) patients with IPAH did not meet current definition criteria assessed during vasodilator testing to assess pulmonary vasodilatory reserve. In those, iloprost-aerosol caused a reduction of mean pulmonary artery pressure (Δ pulmonary artery pressure—11.4%; p<0.001) and increased cardiac output (Δ cardiac output +16.7%; p<0.001), resulting in a reduction of pulmonary vascular resistance (Δ pulmonary vascular resistance—25%; p<0.001). The magnitude of this response was pronounced in surviving patients. A pulmonary vascular resistance reduction of ≥30% turned out to predict outcome in patients with IPAH. Conclusions: Residual pulmonary vasodilative reserve during acute vasodilator testing is of prognostic relevance in patients with IPAH not meeting current definitions of acute vasoreactivity. Therefore vasoreactivity testing holds more information than currently used

Residual pulmonary vasodilative reserve predicts outcome in idiopathic pulmonary hypertension

Objective: Idiopathic pulmonary arterial hypertension (IPAH) remains a devastating and incurable, albeit treatable condition. Treatment response is not uniform and parameters that help to anticipate a rather benign or a malignant course of the disease are warranted. Acute pulmonary vasoreactivity testing during right heart catheterisation is recommended to identify a minority of patients with IPAH with sustained response to calcium channel blocker therapy. This study aimed to evaluate the prognostic significance of a residual pulmonary vasodilative reserve in patients with IPAH not meeting current vasoresponder criteria. Design: Observational right heart catheter study in 66 (n=66) patients with IPAH not meeting current vasoresponse criteria. Pulmonary vasodilative reserve was assessed by inhalation of 5 µg iloprost-aerosol. Results: Sixty-six (n=66) of 72 (n=72) patients with IPAH did not meet current definition criteria assessed during vasodilator testing to assess pulmonary vasodilatory reserve. In those, iloprost-aerosol caused a reduction of mean pulmonary artery pressure (Δ pulmonary artery pressure—11.4%; p<0.001) and increased cardiac output (Δ cardiac output +16.7%; p<0.001), resulting in a reduction of pulmonary vascular resistance (Δ pulmonary vascular resistance—25%; p<0.001). The magnitude of this response was pronounced in surviving patients. A pulmonary vascular resistance reduction of ≥30% turned out to predict outcome in patients with IPAH. Conclusions: Residual pulmonary vasodilative reserve during acute vasodilator testing is of prognostic relevance in patients with IPAH not meeting current definitions of acute vasoreactivity. Therefore vasoreactivity testing holds more information than currently used

Chronic thromboembolic pulmonary hypertension and impairment after pulmonary embolism: the FOCUS study

AIMS: To systematically assess late outcomes of acute pulmonary embolism (PE) and to investigate the clinical implications of post-PE impairment (PPEI) fulfilling prospectively defined criteria. METHODS AND RESULTS: A prospective multicentre observational cohort study was conducted in 17 large-volume centres across Germany. Adult consecutive patients with confirmed acute symptomatic PE were followed with a standardized assessment plan and pre-defined visits at 3, 12, and 24 months. The co-primary outcomes were (i) diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH), and (ii) PPEI, a combination of persistent or worsening clinical, functional, biochemical, and imaging parameters during follow-up. A total of 1017 patients (45% women, median age 64 years) were included in the primary analysis. They were followed for a median duration of 732 days after PE diagnosis. The CTEPH was diagnosed in 16 (1.6%) patients, after a median of 129 days; the estimated 2-year cumulative incidence was 2.3% (1.2-4.4%). Overall, 880 patients were evaluable for PPEI; the 2-year cumulative incidence was 16.0% (95% confidence interval 12.8-20.8%). The PPEI helped to identify 15 of the 16 patients diagnosed with CTEPH during follow-up (hazard ratio for CTEPH vs. no CTEPH 393; 95% confidence interval 73-2119). Patients with PPEI had a higher risk of re-hospitalization and death as well as worse quality of life compared with those without PPEI. CONCLUSION: In this prospective study, the cumulative 2-year incidence of CTEPH was 2.3%, but PPEI diagnosed by standardized criteria was frequent. Our findings support systematic follow-up of patients after acute PE and may help to optimize guideline recommendations and algorithms for post-PE care

DR haplotype diversity of the cynomolgus macaque as defined by its transcriptome

The DR region of particular primate species may display allelic polymorphism and gene copy number variation (region configuration polymorphism). The sum of these distinct types of polymorphism is defined as complexity. To date, however, the DR region of cynomolgus macaques (Macaca fascicularis) has been poorly defined. Transcriptome analysis of a pedigreed colony, comprising animals from Indonesia and Indochina, revealed a total of 15 Mafa-DRA and 57 DRB alleles, specifying 28 different region configurations. The DRA alleles can be divided into two distinct lineages. One lineage is polymorphic, but the majority of the amino acid replacements map to the leader peptide. The second lineage is at best oligomorphic, and segregates with one specific Mafa-DRB allele. The number of Mafa-DRB genes ranges from two to five per haplotype. Due to the presence of pseudogenes, however, each haplotype encodes only one to three bona fide DRB transcripts. Depending on the region configuration in which the Mafa-DRB gene is embedded, identical alleles may display differential transcription levels. Region configurations appear to have been generated by recombination-like events. When genes or gene segments are relocated, it seems plausible that they may be placed in the context of distinct transcription control elements. As such, DRB region-related transcription level differences may add an extra layer of polymorphism to this section of the adaptive immune system

Extensive DRB region diversity in cynomolgus macaques: recombination as a driving force

The DR region of primate species is generally complex and displays diversity concerning the number and combination of distinct types of DRB genes present per region configuration. A highly variable short tandem repeat (STR) present in intron 2 of nearly all primate DRB genes can be utilized as a quick and accurate high through-put typing procedure. This approach resulted previously in the description of unique and haplotype-specific DRB-STR length patterns in humans, chimpanzees, and rhesus macaques. For the present study, a cohort of 230 cynomolgus monkeys, including self-sustaining breeding groups, has been examined. MtDNA analysis showed that most animals originated from the Indonesian islands, but some are derived from the mainland, south and north of the Isthmus of Kra. Haplotyping and subsequent sequencing resulted in the detection of 118 alleles, including 28 unreported ones. A total of 49 Mafa-DRB region configurations were detected, of which 28 have not yet been described. Humans and chimpanzees possess a low number of different DRB region configurations in concert with a high degree of allelic variation. In contrast, however, allelic heterogeneity within a given Mafa-DRB configuration is even less frequently observed than in rhesus macaques. Several of these region configurations appear to have been generated by recombination-like events, most probably propagated by a retroviral element mapping within DRB6 pseudogenes, which are present on the majority of haplotypes. This undocumented high level of DRB region configuration-associated diversity most likely represents a species-specific strategy to cope with various pathogens