Pulmonary embolism and pulmonary hypertension: two issues often neglected in cardiology.

Pulmonary embolism and hypertension are important causes of disability and death in cardiovascular patients. Unfortunately, they often do not receive the attention they deserve, in part because symptoms are similar to those of other more frequent cardiovascular conditions such as acute heart failure and acute coronary syndromes. The European Society of Cardiology (ESC) published guidelines in 2008 and more recently also an updated review on the management of acute pulmonary embolism as well as guidelines on pulmonary hypertension to help clinicians manage this condition. Both manuscripts have been highly cited and downloaded, reflecting the needs of practising physicians. One has to also keep in mind that it is not only the acute management of such patients which is of importance, but also their long-term follow-up. The latter is associated with a significant disease burden. Thus, this issue comes just at the right time, reporting on novel developments in the treatment of pulmonary embolism and hypertension. In a first truly innovative, but preliminary paper, Nils Kucher from the Inselspital in Bern, Switzerland described the use of ‘Fixed low-dose ultrasound-assisted catheter-directed thrombolysis for intermediate and high-risk pulmonary embolism’. The author’s retrospective analysis included 52 patients of whom 14 had troponin-positive high-risk and 38 intermediate-risk pulmonary embolism treated with i.v. unfractionated heparin and ultrasound-assisted catheter-directed thrombolysis with 10 mg of recombinant tissue plasminogen activator. During the 3-month follow-up, two patients died. Major non-fatal bleeding occurred in another two. Mean pulmonary artery pressure decreased significantly from 37+ 9 mmHg at baseline to 25+8 mmHg, and cardiac index increased from 2.0+ 0.7 to 2.7+0.9 L/min/m. The echocardiographic right to left ventricular dimension ratio also decreased from 1.4+0.2 to 1.1+0.2 at 24 h. Of note, the greatest haemodynamic benefit was found in high-risk pulmonary embolism and in those with symptoms of ,14 days. The authors conclude that a standardized fixed low-dose ultrasound-assisted catheterdirected thrombolysis is associated with rapid haemodynamic improvement in intermediate-risk and high-risk pulmonary embolism with low rates of bleeding complications and mortality. This paper complements a recently published systematic review by Engelberger and Kucher, and further supports the need for a large randomized trial using this technology in intermediateand high-risk patients in order to confirm or refute these promising early findings. The second paper, a systematic review and meta-analysis entitled ‘Systemic thrombolytic therapy for acute pulmonary embolism’ by Christophe Albéric Marti from the Geneva University Hospital in Switzerland, determined the risks and benefits of thrombolytic therapy in patients with acute pulmonary embolism. Marti et al. reviewed randomized controlled studies comparing systemic thrombolytic therapy plus anticoagulation with anticoagulation alone. Fifteen trials involving 2057 patients were included. Compared with heparin, thrombolytic therapy was associated with a significant reduction in overall mortality. This reduction, however, was not significant after exclusion of studies enrolling high-risk pulmonary embolism. Thrombolytic therapy was associated with a significant reduction in the combined endpoint of death or treatment escalation, mortality related to pulmonary embolism, and recurrence. Major haemorrhage and fatal or intracranial bleeding were significantly more frequent among patients receiving thrombolysis. The authors conclude that in patients with acute pulmonary embolism, thrombolytic therapy reduces total and embolism-related mortality and recurrence, but is associated with increased major, fatal, or intracranial haemorrhage. Interestingly, in haemodynamically stable patients, overall mortality remained unaffected, suggesting that systemic thrombolysis should be used preferentially in unstable patients. In the third paper, ‘Effect of nocturnal oxygen and acetazolamide on exercise performance in patients with precapillary pulmonary hypertension and sleep-disturbed breathing: randomized, double-blind, cross-over trial’, Silvia Ulrich from the University Hospital Zurich, Switzerland reports their three-period trial. Sleep-disturbed breathing is common in pre-capillary pulmonary hypertension and impairs daytime vigilance. The effects of nocturnal oxygen therapy or acetazolamide on exercise performance and quality of life, on the other hand, remain unknown. Participants received nocturnal oxygen at a dose of 3 L/min, acetazolamide at a dose of 2 × 250 mg daily or sham nocturnal oxygen and placebo tablets, respectively. During 1 week with 1 week washout between the treatments periods. Twenty-three patients with pulmonary hypertension and sleepdisturbed breathing participated. Nocturnal oxygen saturation