Syncope and collapse in acute pulmonary embolism

BACKGROUND

Syncope and collapse (=presyncope) are 2 symptoms of pulmonary embolism (PE), which are suspected of being connected with poorer outcome, regardless of haemodynamic instability. However, pathomechanisms are not completely understood. We aimed to investigate these pathomechanisms in regard to blood pressure and heart rate of syncope/collapse in PE.

METHODS

We performed a retrospective study of consecutive PE patients, who were treated in the Internal Medicine Department. Patients with and without syncope/collapse were compared. Regression models for associations between syncope/collapse and blood pressure, heart rate and shock index (SI) were computed. Moreover we calculated ROC analyses and Youden indices for effectiveness and cut-off-values of these parameters for the probability of syncope/collapse.

RESULTS

182 patients (mean-age 68.5±15.3years; 61.5% female) with confirmed PE were included in this study. 20 PE patients (11.0%) showed a syncope/collapse. PE patients with syncope/collapse were in median 7.5years older (78.5 (72.0/82.3) vs. 71.0 (61.0/80.0) years, P=.0575), had lower systolic (132.0 (108.8/154.0) vs. 145.5 (127.0/166.0) mmHg, P=.0845) and diastolic (70.0±27.0 vs. 78.4±18.4mmHg, P=.0740) blood pressure, whereas heart rate (103.5 (87.8/116.0) vs. 90.0 (76.0/102.0)beats/min, P=.0518), SI (0.78 (0.65/1.01) vs. 0.60(0.50/0.79), P=.0127) and frequency of right ventricular dysfunction (RVD) (88.2% vs. 55.8%, P=.0294) were higher in PE patients with syncope/collapse than in those without. Hypotension (systolic blood pressure<90mmHg), tachycardia and SI>1.0were connected with 6.4-fold, 2.5-fold and 5.8-fold higher probability of syncope/collapse, respectively. ROC analyses revealed cut-off values of ≤110mmHg, ≥107beats/min and >0.62 for systolic blood pressure, heart rate and SI with low AUC values, respectively.

CONCLUSIONS

The pathomechanism of syncope/collapse in patients with acute PE seems to be connected with blood pressure fall, heart rate increase and RVD, in terms of cardiovascular syncope with reduced cardiac output and vasovagal reflex.

The risk factor age in normotensive patients with pulmonary embolism: Effectiveness of age in predicting submassive pulmonary embolism, cardiac injury, right ventricular dysfunction and elevated systolic pulmonary artery pressure in normotensive pulmonary embolism patients

INTRODUCTION

Right ventricular dysfunction (RVD), submassive pulmonary embolism (PE), elevated systolic pulmonary artery pressure (sPAP), elevated cardiac troponin I (cTnI) and old age are well-known risk factors for poor outcome in acute normotensive PE. The aim of this analysis was to calculate age cut-off values to predict submassive PE, cardiac injury, RVD and elevated sPAP in normotensive PE patients.

METHODS

Retrospective analysis of clinical, laboratory, radiological and echocardiographic data of normotensive PE patients (2006-2011) was performed. Receiver operating characteristic (ROC) curves and Youden indexes were used to test the effectiveness of using patients' ages at the PE event to predict a submassive PE, cardiac injury (elevated cTnI >0.1ng/ml), RVD and elevated sPAP (>30mmHg) in normotensive PE patients and to calculate optimal cut-off values. Patients >76years were compared to those aged ≤76years.

RESULTS

129 normotensive PE patients (59.7% women) met the inclusion criteria and were included in this analysis. The optimal cut-off value for patient ages to predict submassive PE, cardiac injury (elevated cTnI >0.1ng/ml), RVD and elevated sPAP (>30mmHg) was 76.5, 81.5, 66.5 and 66.5years, respectively, with moderate effectiveness (AUC 0.69, 0.58, 0.71 and 0.69, respectively). Patients >76years old had higher percentages of submassive PE (91.1% vs. 63.1%, P=0.000680), RVD (91.1% vs. 58.3%, P=0.000119), sPAP (42.64±16.70 vs. 29.24±17.56mmHg, P=0.000044) and cTnI (0.22±0.40 vs. 0.10±0.25ng/ml, P=0.00488).

CONCLUSIONS

Age is an important prognostic factor in acute normotensive PE. In addition to cTn and RVD, age should be taken into account in determining the risk stratification for acute PE.