Preeclampsia: What It Is, Symptoms, Risk Factors, Treatment & Prevention
Heart CT Scan Parameter Predicts Cardiovascular Events In PH
A higher diameter ratio on CT scans between the right ventricle and left ventricle, which are the heart's lower chambers, independently predicts major adverse cardiovascular events in people with pulmonary hypertension (PH), a study reports.
"In our study, the [right ventricle/left ventricle] ratio not only well reflected PH severity, but also emerged as the strongest predictor of MACE [major adverse cardiovascular events]," the researchers wrote.
In addition, the size of the main pulmonary artery attached to the heart and its ratio with the ascending aorta, the major blood vessel that transports oxygen-rich blood from the heart, were also reliable indicators of PH severity, data shows.
"Identifying a noninvasive and simple CT imaging parameter that reflects PH severity could help identify clinically overlooked PH patients and provide guidance for further evaluation," the researchers wrote. The study, "CT imaging biomarkers to predict severity and prognosis of pulmonary hypertension," was published in PLOS One.
PH is a progressive disease associated with high blood pressure in the pulmonary arteries, the blood vessels that carry oxygen-poor blood from the heart to the lungs to be oxygenated. Because the right side of the heart pumps blood through these arteries, the pushback from elevated blood pressure can lead to right heart damage and failure.
The gold standard for PH diagnosis is right heart catheterization, or RHC, wherein a thin, flexible catheter is inserted into a vein in the neck, arm, or groin and passed into the right ventricle and pulmonary artery. This method can directly measure mean pulmonary artery pressure, or mPAP, and reveal the heart's capacity to pump blood.
Because RHC is invasive and cannot be repeated often, physicians use the noninvasive echocardiogram, which creates images of the heart and blood vessels, to evaluate heart enlargement and heart wall thickening, and to estimate mPAP. Echocardiographic evaluation is challenging for people with obesity or advanced lung disease, however.
A CT scan is another noninvasive imaging technique that has several advantages in diagnosing PH, including being able to rapidly visualize the pulmonary arteries and the right heart structure. Still, data on which CT measurements reflect PH severity or predict major adverse cardiovascular events are limited.
Predicting cardiovascular eventsTo address this, researchers in South Korea retrospectively analyzed data from 144 people who had heart CT scans and RHC for suspected PH. They then looked for relationships between CT imaging parameters and RHC-assessed mPAP.
The patients' mean age was 57.7 and more than half (57.4%) were women. Nearly half (41.2%) had high blood pressure, nearly 1 in 4 (23.3%) had altered blood fats, and nearly 1 in 5 (19.6%) had diabetes. Some patients had coronary artery disease (12.2%), where the blood supply to the heart is reduced or interrupted, or pulmonary thromboembolism (14.9%), where a blood clot blocks blood flow in the pulmonary arteries.
Based on mPAP values from RHC, most patients (80.2%) were eventually diagnosed with PH.
CT scans were analyzed to measure the size of the large blood vessels connected to the heart and the size of each ventricle. The septal angle, formed between the wall separating the two ventricles and the chest midline, was also assessed.
According to CT scan data, all the pulmonary artery diameters increased significantly with increasing mPAP values, reflecting more severe PH. These included the main pulmonary arteries, the left and right pulmonary arteries supplying each lung, and the ratio of the pulmonary artery and ascending aorta.
The diameter of the right ventricle and right atrium (the heart's upper chamber), the right and left ventricles (RV/LV) ratio, the right and left atriums ratio, and the septal angle also significantly increased with increasing mPAP values.
Over a median follow-up of 36 months and up to 115 months, or about 9.5 years, 44 patients (30.6%) had major adverse cardiovascular events, resulting in 30 hospitalizations and 14 deaths.
Statistical analyses adjusted for potential influencing factors showed that a high RV/LV ratio was the best independent predictor of MACE, being significantly associated with a twofold higher risk. Older age was the second best predictor, being linked to a 3% higher risk. Pulmonary thromboembolism was not predictive of MACE, the researchers said.
"Among CT parameters, the RV/LV ratio was the strongest predictor of MACE in patients with PH, while the [pulmonary artery size] and [pulmonary to aorta ratio] were the reliable indicators reflecting mPAP levels," they wrote.
Pulmonary Hypertension Subtypes Show Distinct PA Flow Hemodynamics
Investigators used 4D flow cardiovascular magnetic resonance imaging to search for differences between pulmonary artery (PA) remodeling in pulmonary arterial hypertension and other types of pulmonary hypertension.
Advanced imaging technology can help clinicians better understand pulmonary artery (PA) remodeling and its relation to different types of pulmonary hypertension (PH), according to a new report. The study was published in the journal Pulmonary Circulation.1
The analysis found that patients with pulmonary arterial hypertension (PAH) had distinct PA flow characteristics compared with those with heart failure with preserved ejection fraction and pulmonary hypertension (PH-HFpEF). These findings suggest the PA remodeling process differs by PH etiology, the authors explained.
Patients with PAH had distinct PA flow characteristics compared with those with PH-HFpEF.Image credit: Thirawat - stock.Adobe.Com
Corresponding author James D. Thomas, MD, of Northwestern University, and colleagues, noted that PH subtypes—including PAH (Group 1) and PH due to left heart disease (Group 2 PH)—are definable by hemodynamic indices.
Group 2 PH is the most common type of PH, and Thomas and colleagues noted that many patients with Group 2 PH meet the criteria for PH-HFpEF, which itself can be subdivided into isolated postcapillary PH and combined pre- and postcapillary PH.
Yet differentiating between the different subtypes can be difficult and invasive. "While these subtypes are distinguishable in advanced disease, early differentiation often requires precise catheterization," they wrote.
One possible solution the authors presented is the use of 4D flow cardiovascular magnetic resonance imaging (4D-flow CMR). It allows for comprehensive assessment of blood flow velocities in the PA, thereby helping clinicians track the progression of PH. The imaging method also makes it possible to track physiological parameters, helping clinicians better characterize vascular remodeling.
Recent research has highlighted the role of advanced MRI to track hemodynamic changes in pulmonary circulation,2 Thomas and colleagues noted. Yet, while studies have examined its ability to track right ventricle (RV) and PA flow, little attention has been devoted toward identifying potential associations between PA flow features and PH etiologies, they said.
The investigators identified 13 patients with PAH and 15 patients with PH-HFpEF and performed echocardiography, 4D-flow CMR, and right heart catheterization on each. They then compared several parameters, including right ventricular outflow tract (RVOT) flow and main pulmonary artery (MPA) hemodynamics, including peak velocity and mean and maximum wall shear stress (WSS).
They found that mean PA pressure and pulmonary vascular resistance (PVR) were higher in patients with PAH. Eight of the 13 patients with PAH also had RVOT systolic notching, compared with 0 patients in the PH-HFpEF group. RVOT acceleration time was shorter in the PAH group, and people with PAH had lower MPA peak velocity, mean WSS, and maximal WSS. Thomas and colleagues also found PVR was negatively correlated with MPA mean WSS.
"These findings align with RHC and echocardiography results, showing higher PVR, more notching patterns, and altered RVOT flow in PAH patients," Thomas and colleagues wrote. "These changes are well-known indicators of pulmonary vascular load and RV function."
The investigators said their findings confirm that PA remodeling in PAH and PH-HFpEF are significantly different due to differences in flow characteristics. They added, though, that some patients with advanced PH-HFpEF and significant PA remodeling may benefit from drugs initially developed to treat PAH.
Thomas and colleagues noted their results should be interpreted with caution due to the study's small sample size. They also explained that their analysis was limited to PA flow, and thus did not capture changes at the cellular level that might further elucidate overall PA remodeling.
Still, they said these early data suggest MPA WSS may serve as an important novel indicator of PA remodeling in patients with PH.
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Pulmonary Physician Streamlines Critical Care Practices With Zero-Complication Protocol
Implementing the ventilator-associated events (VAE) prevention protocol at Community Health Network has yielded remarkable results. After two years of adherence to the structured, evidence-based approach, the ICU has reported zero complications, demonstrating its effectiveness in improving critical care.
Dr. Sathish Krishnan, a pulmonary and critical care physician at Community Health Network in Indianapolis, leads this initiative. His methodical approach enhances ICU standards while contributing to advancements in pulmonary hypertension (PH) care, interstitial lung disease (ILD) treatment, and early lung cancer detection.
Advancing Pulmonary Hypertension and Critical CareDr. Sathish Krishnan has been pivotal in developing the pulmonary hypertension program, overcoming significant challenges such as securing institutional support, integrating multidisciplinary teams, and ensuring adherence to evolving pulmonary hypertension treatment guidelines. His efforts have helped establish a structured framework for patient care, paving the way for improved access to specialized treatment and streamlined diagnostic protocols at Community Health Network, working towards its accreditation as a Comprehensive Pulmonary Hypertension Care Center — one of only three such centers in Indiana.
Pulmonary hypertension is a rare but life-threatening condition. A 2019 study reported that there are only 257 pulmonary hypertension specialists nationwide, highlighting the critical need for more expertise in this field. His contributions ensure better access to specialized care for pulmonary hypertension patients and improved treatment strategies.
Beyond pulmonary hypertension, Dr. Sathish Krishnan is one of fewer than 15 pulmonologists in Indiana trained in robotic bronchoscopy, an advanced technique for early lung cancer detection. With low-dose CT screenings increasing early lung cancer diagnoses, robotic bronchoscopy is essential in confirming malignancies with minimal invasiveness.
Breakthrough Research and Clinical TrialsDr. Sathish Krishnan is taking point in groundbreaking research, contributing to advancements that have influenced treatment protocols and informed policy changes in pulmonary medicine. As a co-investigator for the TETON and TETON OLE clinical trials, he is helping evaluate inhaled Treprostinil's efficacy in treating idiopathic pulmonary fibrosis (IPF). These large, multi-center trials, sponsored by United Therapeutics, could fundamentally change treatment strategies for this serious disease, marking a potential breakthrough in IPF care.
His contributions extend to medical literature, with numerous publications focused on rare diseases and atypical presentations, helping clinicians worldwide recognize and manage complex cases. His Google Scholar profile reflects his ongoing impact on pulmonary medicine.
Addressing Systemic ChallengesThe challenge of preventing ventilator-associated complications is not new. Hospital-acquired infections (HAI) remain a significant burden on the U.S. Healthcare system, with an estimated 687,000 cases reported annually. The mortality rate for ventilator-associated pneumonia alone can reach 30% in high-risk populations.
Dr. Sathish Krishnan has advanced critical care delivery by implementing a proactive approach. As the ICU director and chair of the Pharmacy and Therapeutic Committee, he has developed hospital-wide best practices that reduce preventable complications.
Contributions to Global Access and Medical EducationDr. Sathish Krishnan is an active member of the Pulmonary Vascular Research Institute (PVRi) "Access to Care" taskforce, where he collaborates with pulmonary hypertension experts worldwide to address disparities in treatment access, both in the U.S. And internationally. His efforts have facilitated global discussions on improving pulmonary hypertension care, particularly in low- and middle-income countries.
His commitment to education and knowledge dissemination is evident through his editorial and peer-review roles in multiple medical journals. He serves as an associate editor for the Journal of Clinical Case Reports, a review board member for Therapeutic Advances in Pulmonary and Critical Care Medicine, and has reviewed abstracts for national conferences such as CHEST, ACP, and SGIM.
Recognized Excellence in Pulmonary MedicineDr. Sathish Krishnan's contributions have earned him national and international recognition. His FCCP designation is awarded to a select group of physicians demonstrating exceptional leadership in pulmonary medicine, and his consecutive recognition as a Top Doctor in Indianapolis places him among the most trusted specialists in his region.
In 2024, he was awarded Fellow of the American College of Chest Physicians (FCCP) and was named a Top Doctor in Indianapolis by Indianapolis Monthly Magazine for three consecutive years (2021–2023).
Pulmonary Care In Five YearsAdvancements in pulmonary hypertension treatment, interstitial lung disease management, and ICU care will modify respiratory medicine in 2030. Dr. Sathish Krishnan believes training programs, interdisciplinary collaboration, and research-driven solutions are key to improving patient outcomes nationwide.
Dr. Sathish Krishnan emphasizes that the objective is to meet existing standards and push the boundaries of excellence in patient care. He highlights that every prevented complication, every early cancer diagnosis, and every breakthrough treatment contributes to a larger shift in how critical care is delivered.
Spencer Hulse is the Editorial Director at Grit Daily. He is responsible for overseeing other editors and writers, day-to-day operations, and covering breaking news.
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