Saddle versus non-saddle pulmonary embolism: differences in the clinical, echocardiographic, and outcome characteristics

Abstract

The central location, the size, and instability of saddle pulmonary embolism (PE) have raised considerable concerns regarding its hemodynamic consequences and the optimal management approach. Sparse and conflicting reports have addressed these concerns in the past. We aimed to evaluate the clinical presentation, hemodynamic and echocardiographic effects, as well as the outcomes of saddle PE, and compare the results with those of non-saddle type. This was a retrospective study of 432 adult patients with saddle and non-saddle PE. Overall, 432 patients were diagnosed with PE by computed tomography pulmonary angiography (CTPA). Seventy-three (16.9%) had saddle PE, and 359 had non-saddle PE. Compared to those with non-saddle PE, patients with saddle PE presented more frequently with tachycardia (68.5% vs. 46.2%, P = .001), and tachypnea (58.9% vs. 42.1%, P = .009) on admission, required more frequent intensive care unit (ICU) admissions (45.8% vs. 26.6%, P = .001) and thrombolysis/thrombectomy use (19.1% vs. 6.7%, P = .001), and were at more risk of developing decompensation and cardiac arrest after their initial admission (15.3% vs. 5.9%, P = .006). On echocardiography, right ventricular (RV) enlargement (60% vs. 31.1%, P = .000), RV dysfunction (45.8% vs. 22%, P = .000), and RV systolic pressure (RVSP) of greater than 40 mmHg (61.5% vs. 39.2%, P = .003) were significantly more observed with saddle PE. The two groups did not differ concerning the rates of hypotension (17.8% vs. 18.7%, P = .864) and hypoxemia (41.1% vs. 34.3%, P = .336) on admission and mortality rates. A logistic regression model indicated that the use of oral contraceptive pills (OCP), RVSP > 40 mmHg, and development of hypotension and decompensation following admission were associated with an increased likelihood of having saddle embolus. Saddle PE accounts for a higher proportion among all PE cases than previously reported. Patients with saddle PE tend to present more frequently with adverse hemodynamic and echocardiographic changes and decompensate after their initial presentation. OCP use, development of hypotension, and decompensation following admission and RVSP > 40 mmHg are significant predictors of saddle PE. These characteristics should not be overlooked when managing patients with saddle PE.

Optimal management, prevalence, and clinical behavior of saddle pulmonary embolism: A systematic review and meta-analysis

“…Although previous studies suggest that SPE accounts for up to 5 % of all PE cases [9], recent reports suggest a figure as high as 17 % among all PE cases [10]. The central location, the large size, and the unstable nature (with the risk of migration and lodging into the main pulmonary arteries or their branches) of SPE have raised considerable concerns regarding the hemodynamic consequences and the optimal treatment for such clots [10,11]. Before the era of computerized tomography (CT) scan techniques, SPE was regarded by many authors as a grave diagnosis because most of the cases were diagnosed at necropsy [9,12].…”

“…The exact incidence of SPE is unknown. Although previous studies suggest that SPE accounts for up to 5 % of all PE cases [9], recent reports suggest a figure as high as 17 % among all PE cases [10]. The central location, the large size, and the unstable nature (with the risk of migration and lodging into the main pulmonary arteries or their branches) of SPE have raised considerable concerns regarding the hemodynamic consequences and the optimal treatment for such clots [10,11].…”

“…Before the era of computerized tomography (CT) scan techniques, SPE was regarded by many authors as a grave diagnosis because most of the cases were diagnosed at necropsy [9,12]. Clinicians' concerns about SPE have been further augmented by recent reports that documented serious hemodynamic consequences and higher mortality rates among SPE patients compared to other PE types [10,13]. Despite the increasing number of publications that addressed the serious consequences of SPE and the recent advances in CT scan techniques that permitted the accurate diagnosis of SPE, most of the recent PE guidelines are devoid of any information regarding the optimal treatment of SPE [2,[14][15][16][17].…”

Prediction of in-hospital adverse clinical outcomes in patients with pulmonary thromboembolism, machine learning based models

“… Saddle embolus was reported higher in our outcome group compared to our event-free group, but this was not statistically significant, probably because of the lower number of saddle emboli than our lobar emboli and segmental emboli patients. Recent studies show that saddle pulmonary embolism results in a higher proportion of hemodynamic instability and other adverse events ( 26 , 27 ). Despite saddle emboli, lobar artery emboli patients had a higher proportion in our population in both groups, so it worked as a helpful variable for outcome prediction.…”

Outcomes of Surgical and Mechanical Thrombectomy in Massive Saddle Pulmonary Embolism: A National Perspective

“…Central pulmonary embolism is diagnosed when thrombi are found in the main trunk of the pulmonary artery and the right or left pulmonary arteries [ 3 ]. Saddle PE refers to a specific type of central PE-an embolus lodged in the bifurcation of the main pulmonary artery trunk, often extending into the right and left pulmonary arteries [ 4 , 5 ]. Saddle emboli are more commonly (but not always) high-risk (super-massive or massive) or intermediate-risk (sub-massive) [ 6 ].…”