Sleep apnea may contribute to PE recurrence

CT scan showing PE

Image from Medical

College of Georgia

Suffering from obstructive sleep apnea (OSA) increases a person’s risk of pulmonary embolism (PE) recurrence, according to a study published in CHEST.

It has been hypothesized that OSA may promote the formation of blood clots.

Because venous thromboembolism is a chronic condition, researchers wanted to examine how OSA affected the rate of repeat PE occurrence.

They found that, after the first PE, OSA increases the risk for recurrence.

“There is growing evidence from cross-sectional and longitudinal studies that obstructive sleep apnea is a risk factor for pulmonary embolism,” explained study author Alberto Alonso-Fernández, MD, PhD, of Hospital Universitario Son Espases, Palma de Mallorca, Spain.

“This association represents a major public health burden, given the high prevalence of both disorders and the mortality rates of PE. However, to our knowledge, no longitudinal studies to date have explored the role of OSA as a risk factor for recurrent thromboembolic events.”

Therefore, Dr Alonso-Fernández and his colleagues followed 120 patients for 5 to 8 years after their first occurrence of PE. The patients were not taking oral anticoagulants at the start of the study.

The patients’ sleep was monitored for signs of OSA. A patient was classified as having OSA when the obstructive component was dominant and the apnea hypopnea index (AHI) was ≥ 10 per hour (10 h^–1).

Nineteen of the patients had recurrent PE during the follow-up period, and 16 of them suffered from OSA.

Multivariate analysis revealed several independent risk factors for recurrent PE, including:

• AHI ≥ 10 h^–1—hazard ratio (HR)=20.7
• Mean nocturnal oxygen saturation (nSaO2)—HR=0.39
• Time with SaO2 < 90% (CT90%)—HR=0.90
• D-dimer level—HR=1.001.

“The main finding in this study is that, after a first episode of PE, patients with OSA had a higher risk of recurrent PE than those without OSA,” Dr Alonso-Fernández said.

“Moreover, AHI and nocturnal hypoxemia, assessed by the mean nocturnal oxygen saturation and percentage of total time the patient spent with their oxygen saturation below 90%, are independent risk factors for PE recurrence and for resuming anticoagulation because of a new thromboembolic event.”

Twenty-four patients resumed oral anticoagulation. Independent risk factors for resuming anticoagulation included:

• AHI ≥ 10 h^–1—HR=20.66
• Mean nSaO2—HR=0.54
• Epworth Sleepiness Scale—HR=0.73.

Explaining the findings

Addressing why OSA may make people more susceptible to subsequent PE events, Dr Alonso-Fernández said, “PE is the result of Virchow’s classic risk triad—namely, vascular endothelial impairment, stasis of blood flow, and/or increased coagulability. OSA could hypothetically affect all 3 mechanistic pathways.”

“Intermittent hypoxia increases oxidative stress and inflammatory response that impairs endothelial function. OSA-related hemodynamic alterations and sedentarism may slow intravenous flow, and lastly, increased coagulability, platelet activity, and decreased fibrinolytic capacity in OSA may be improved after CPAP [continuous positive airway pressure].”

Several factors have been identified as playing a role in recurrent PE, including cancer, continued estrogen use, vena cava filters, high post-anticoagulation D-dimer, male gender, and obesity.

The current study suggested that OSA is an independent risk factor for recurrent PE, even after adjusting for several factors, including body mass index. OSA is a common problem among obese people, and the researchers assert that the risk of recurrent PE that is attributed to obesity might be partially related to OSA.

“Obesity is associated with sedentarism and venous stasis, and it has also been related to impaired fibrinolysis and high concentrations of clotting factors that might lead to a prothrombotic state that can further increase because obesity is associated with high estrogen levels and chronic low-grade inflammation,” Dr Alonso-Fernández said.

“It is tempting to speculate that OSA and obesity may additively or synergistically lead to upregulation of procoagulant activity that may intensify the risk of PE recurrence.”

Dr Alonso-Fernández and his colleagues believe that knowing OSA is an independent risk factor for recurrent PE can help physicians better understand treatment options. CPAP use is a proven intervention for OSA, and patients with OSA may need to stay on anticoagulation therapy longer to reduce their risk for another PE.

“Given the high prevalence of OSA in patients with PE, the procoagulable state induced by the intermittent hypoxia, and the risk for PE recurrence, the potential of CPAP and/or extend oral anticoagulation to reduce PE recurrence and mortality in patients with PE and OSA clearly warrants further study,” Dr Alonso-Fernández concluded.

CT scan showing PE

Image from Medical

College of Georgia

Suffering from obstructive sleep apnea (OSA) increases a person’s risk of pulmonary embolism (PE) recurrence, according to a study published in CHEST.

It has been hypothesized that OSA may promote the formation of blood clots.

Because venous thromboembolism is a chronic condition, researchers wanted to examine how OSA affected the rate of repeat PE occurrence.

They found that, after the first PE, OSA increases the risk for recurrence.

“There is growing evidence from cross-sectional and longitudinal studies that obstructive sleep apnea is a risk factor for pulmonary embolism,” explained study author Alberto Alonso-Fernández, MD, PhD, of Hospital Universitario Son Espases, Palma de Mallorca, Spain.

“This association represents a major public health burden, given the high prevalence of both disorders and the mortality rates of PE. However, to our knowledge, no longitudinal studies to date have explored the role of OSA as a risk factor for recurrent thromboembolic events.”

Therefore, Dr Alonso-Fernández and his colleagues followed 120 patients for 5 to 8 years after their first occurrence of PE. The patients were not taking oral anticoagulants at the start of the study.

The patients’ sleep was monitored for signs of OSA. A patient was classified as having OSA when the obstructive component was dominant and the apnea hypopnea index (AHI) was ≥ 10 per hour (10 h^–1).

Nineteen of the patients had recurrent PE during the follow-up period, and 16 of them suffered from OSA.

Multivariate analysis revealed several independent risk factors for recurrent PE, including:

• AHI ≥ 10 h^–1—hazard ratio (HR)=20.7
• Mean nocturnal oxygen saturation (nSaO2)—HR=0.39
• Time with SaO2 < 90% (CT90%)—HR=0.90
• D-dimer level—HR=1.001.

“The main finding in this study is that, after a first episode of PE, patients with OSA had a higher risk of recurrent PE than those without OSA,” Dr Alonso-Fernández said.

“Moreover, AHI and nocturnal hypoxemia, assessed by the mean nocturnal oxygen saturation and percentage of total time the patient spent with their oxygen saturation below 90%, are independent risk factors for PE recurrence and for resuming anticoagulation because of a new thromboembolic event.”

Twenty-four patients resumed oral anticoagulation. Independent risk factors for resuming anticoagulation included:

• AHI ≥ 10 h^–1—HR=20.66
• Mean nSaO2—HR=0.54
• Epworth Sleepiness Scale—HR=0.73.

Explaining the findings

Addressing why OSA may make people more susceptible to subsequent PE events, Dr Alonso-Fernández said, “PE is the result of Virchow’s classic risk triad—namely, vascular endothelial impairment, stasis of blood flow, and/or increased coagulability. OSA could hypothetically affect all 3 mechanistic pathways.”

“Intermittent hypoxia increases oxidative stress and inflammatory response that impairs endothelial function. OSA-related hemodynamic alterations and sedentarism may slow intravenous flow, and lastly, increased coagulability, platelet activity, and decreased fibrinolytic capacity in OSA may be improved after CPAP [continuous positive airway pressure].”

Several factors have been identified as playing a role in recurrent PE, including cancer, continued estrogen use, vena cava filters, high post-anticoagulation D-dimer, male gender, and obesity.

The current study suggested that OSA is an independent risk factor for recurrent PE, even after adjusting for several factors, including body mass index. OSA is a common problem among obese people, and the researchers assert that the risk of recurrent PE that is attributed to obesity might be partially related to OSA.

“Obesity is associated with sedentarism and venous stasis, and it has also been related to impaired fibrinolysis and high concentrations of clotting factors that might lead to a prothrombotic state that can further increase because obesity is associated with high estrogen levels and chronic low-grade inflammation,” Dr Alonso-Fernández said.

“It is tempting to speculate that OSA and obesity may additively or synergistically lead to upregulation of procoagulant activity that may intensify the risk of PE recurrence.”

Dr Alonso-Fernández and his colleagues believe that knowing OSA is an independent risk factor for recurrent PE can help physicians better understand treatment options. CPAP use is a proven intervention for OSA, and patients with OSA may need to stay on anticoagulation therapy longer to reduce their risk for another PE.

“Given the high prevalence of OSA in patients with PE, the procoagulable state induced by the intermittent hypoxia, and the risk for PE recurrence, the potential of CPAP and/or extend oral anticoagulation to reduce PE recurrence and mortality in patients with PE and OSA clearly warrants further study,” Dr Alonso-Fernández concluded.

CT scan showing PE

Image from Medical

College of Georgia

Suffering from obstructive sleep apnea (OSA) increases a person’s risk of pulmonary embolism (PE) recurrence, according to a study published in CHEST.

It has been hypothesized that OSA may promote the formation of blood clots.

Because venous thromboembolism is a chronic condition, researchers wanted to examine how OSA affected the rate of repeat PE occurrence.

They found that, after the first PE, OSA increases the risk for recurrence.

“There is growing evidence from cross-sectional and longitudinal studies that obstructive sleep apnea is a risk factor for pulmonary embolism,” explained study author Alberto Alonso-Fernández, MD, PhD, of Hospital Universitario Son Espases, Palma de Mallorca, Spain.

“This association represents a major public health burden, given the high prevalence of both disorders and the mortality rates of PE. However, to our knowledge, no longitudinal studies to date have explored the role of OSA as a risk factor for recurrent thromboembolic events.”

Therefore, Dr Alonso-Fernández and his colleagues followed 120 patients for 5 to 8 years after their first occurrence of PE. The patients were not taking oral anticoagulants at the start of the study.

The patients’ sleep was monitored for signs of OSA. A patient was classified as having OSA when the obstructive component was dominant and the apnea hypopnea index (AHI) was ≥ 10 per hour (10 h^–1).

Nineteen of the patients had recurrent PE during the follow-up period, and 16 of them suffered from OSA.

Multivariate analysis revealed several independent risk factors for recurrent PE, including:

• AHI ≥ 10 h^–1—hazard ratio (HR)=20.7
• Mean nocturnal oxygen saturation (nSaO2)—HR=0.39
• Time with SaO2 < 90% (CT90%)—HR=0.90
• D-dimer level—HR=1.001.

“The main finding in this study is that, after a first episode of PE, patients with OSA had a higher risk of recurrent PE than those without OSA,” Dr Alonso-Fernández said.

“Moreover, AHI and nocturnal hypoxemia, assessed by the mean nocturnal oxygen saturation and percentage of total time the patient spent with their oxygen saturation below 90%, are independent risk factors for PE recurrence and for resuming anticoagulation because of a new thromboembolic event.”

Twenty-four patients resumed oral anticoagulation. Independent risk factors for resuming anticoagulation included:

• AHI ≥ 10 h^–1—HR=20.66
• Mean nSaO2—HR=0.54
• Epworth Sleepiness Scale—HR=0.73.

Explaining the findings

Addressing why OSA may make people more susceptible to subsequent PE events, Dr Alonso-Fernández said, “PE is the result of Virchow’s classic risk triad—namely, vascular endothelial impairment, stasis of blood flow, and/or increased coagulability. OSA could hypothetically affect all 3 mechanistic pathways.”

“Intermittent hypoxia increases oxidative stress and inflammatory response that impairs endothelial function. OSA-related hemodynamic alterations and sedentarism may slow intravenous flow, and lastly, increased coagulability, platelet activity, and decreased fibrinolytic capacity in OSA may be improved after CPAP [continuous positive airway pressure].”

Several factors have been identified as playing a role in recurrent PE, including cancer, continued estrogen use, vena cava filters, high post-anticoagulation D-dimer, male gender, and obesity.

The current study suggested that OSA is an independent risk factor for recurrent PE, even after adjusting for several factors, including body mass index. OSA is a common problem among obese people, and the researchers assert that the risk of recurrent PE that is attributed to obesity might be partially related to OSA.

“Obesity is associated with sedentarism and venous stasis, and it has also been related to impaired fibrinolysis and high concentrations of clotting factors that might lead to a prothrombotic state that can further increase because obesity is associated with high estrogen levels and chronic low-grade inflammation,” Dr Alonso-Fernández said.

“It is tempting to speculate that OSA and obesity may additively or synergistically lead to upregulation of procoagulant activity that may intensify the risk of PE recurrence.”

Dr Alonso-Fernández and his colleagues believe that knowing OSA is an independent risk factor for recurrent PE can help physicians better understand treatment options. CPAP use is a proven intervention for OSA, and patients with OSA may need to stay on anticoagulation therapy longer to reduce their risk for another PE.

“Given the high prevalence of OSA in patients with PE, the procoagulable state induced by the intermittent hypoxia, and the risk for PE recurrence, the potential of CPAP and/or extend oral anticoagulation to reduce PE recurrence and mortality in patients with PE and OSA clearly warrants further study,” Dr Alonso-Fernández concluded.