Introduction: Pulmonary embolism is a serious disease and common among hospitalized patients. The incidence of pulmonary embolism in Iceland is largely unknown. The purpose of this study was to  evaluate the incidence, clinical presentation, risk factors and outcome among patients diagnosed with pulmonary embolism  at Landspítali, The National University Hospital of Iceland.

Material and methods: A retrospective analysis of  medical records of patients diagnosed with the ICD-10 diagnosis I26 (Pulmonary embolism) between 2005-2007 was carried out. Data were retrieved on age, clinical manifestations, treatment, risk factors, diagnostic procedures and outcome.

Results: The total number of patients was 312 and the in-hospital incidence was 5 per 1.000. Thirty day mortality was 9.9% (95% CI 6.6-13.3). Dyspnea was the most common symptom (81%) and diagnosis was most often established by computed tomography of the pulmonary vasculature (88,8%). Anticoagulation was by far the most common management (96%) but thrombolysis, thrombectomy or use of inferior vena cava filters were very rare. The frequency of atrial fibrillation was significantly more common in patients with pulmonary hypertension by echocardiography than without, 32.4% and 9.7%, respectively (p= 0.026). Thirty day mortality was significantly higher in women than in men (13.2% versus 6.5%, p=0.049), and in patients with no classic symptoms of pulmonary embolism at diagnosis (36.4% versus 8.1%, p=0.012).

Discussion: The hospital incidence of pulmonary embolism, 5/1000 patients, at Landspitali The National University Hospital of Iceland is higher than found in similar studies in many other countries. Mortality, while similar, has fallen markedly during the past 40 years.

Jonsson KO^1,2, Agnarsson UTh², Danielsen R², Thorgeirsson G¹

University of Iceland¹, Landspítali,The National University Hospital of Iceland, Department of Cardiology²

Dyspnea		81%
Chest pain		39%
DVT		31%
Chest tightness		17%
Syncope		13%
None of the above		4%

Figure 1

: Major manifestations at the time of diagnosis, expressed as a proportion of patients with each manifestation.

CTPA- 88,8%		277
V/Q scan - 4,2%		13
Autopsy - 2,2%		7
Clinical, after death - 1,9%		6
Clinical - 1,9%		6
CTPA & V/Q scan - 1,0%		3

Figure 2

: Methods of diagnosis of pulmonary embolism, expressed as a percentage of all patients.

Right ventricular pressure overload		34%
Inverted T-waves		32%
Sinus tachycardia		30%
Right ventricular strain		18%
Atrial fibrillation		14%
Right axis		13%
S1Q3T3		11%
Incomplete right bundle branch block		11%
Right bundle branch block		9%
Normal EKG		30%

Figure 3

: Findings on electrocardiograms obtained within three days from diagnosis of pulmonary embolism, expressed as a percentage of patients with electrocardiographic finding. Right ventricular pressure overload was identified with the presence of one of the following: Right axis deviation, S1Q3T3, right bundle branch blosk, complete or incomplete or ST-T changes in V1-V3.

Enlarged right ventricle		41%
Pulmonary hypertension		56%
Flat left ventricular septum		8%
Enlarged right ventricle and pulmonary hypertension		36%
Normal cardiac ultrasound		39%

Figure 4

: Echocardiographic changes within a week from diagnosis, expressed as a proportion of patients with each echocardiographic finding.

 

Table I: Patient characteristics, underlying diseases, risk factors and outcomes.

Patient characteristics
	All patients	Deceased within 30 days	Alive after 30 days
Number of patients	312	31	281
Average age ± standard deviation [median]	68,3 ±16,4 [72,5]	75,5 ±17,2 [79]	67,5 ±16,1 [71]
Gender ratio(M:F)	153:159	10:21	142:138
Diseases & risk factors	% (n)	% (n)	% (n)	P-value
Arterial hypertension	36,2 (113)	32,3 (10)	36,7 (103)	0,629
Cancer history	19,2 (60)	38,7 (12)	17,1 (48)	0,004
Ischemic heart disease	13,8 (43)	19,4 (6)	13,2 (37)	0,343
Prior history of venous thromboembolic disease	11,2 (35)	12,9 (4)	11,0 (31)	0,754
Recent fracture/operation	12,5 (39)	9,7 (3)	12,8 (36)	0,617
Chronic obstructive pulmonary disease	10,9 (34)	19,4 (6)	10,0 (28)	0,111
Recent travel	9,3 (29)	3,2 (1)	10,0 (28)	0,220
Paresis/prolonged bed rest	6,1 (19)	12,9 (4)	5,3 (15)	0,095
History of myocardial infarction	3,5 (11)	6,5 (2)	3,2 (9)	0,352
No risk factors	23,7 (74)	6,5 (2)	25,6 (72)	0,017

Table II: Management of patients with pulmonary embolism. Some patients received more than one form of treatment.

Treatment	(N) %
Anticoagulation therapy	289 (96,0)
Thrombolysis	12 (4,0)
Vena cava filter	7 (2,3)
Thrombectomy	1 (0,3)
None	10 (3,3)
Insufficient data	11 (3,5)