Echocardiographic characterization and markers of cardiovascular risk in adults with sickle cell disease in a Colombian tertiary referral centre: a cross-sectional study

In a cross-sectional study of 57 adults with sickle cell disease in Colombia, echocardiographic analysis revealed that while biventricular structure and function were largely preserved, nearly one-third of patients exhibited signs suggestive of pulmonary hypertension, supporting the routine use of echocardiography for early cardiovascular risk stratification in this population.

The Gist

The Heart of the Matter: A Story of Sickle Cell in Colombia

Imagine the human body as a bustling city. In people with Sickle Cell Disease (SCD), the delivery trucks (red blood cells) that usually carry oxygen are misshapen. Instead of being smooth and round, they are stiff and crescent-shaped. These "sickle" trucks get stuck in traffic jams (blood vessels), causing delays, damage to the roads, and a shortage of oxygen for the city's buildings.

Over time, this constant traffic jam puts a huge strain on the city's power plant: the heart.

This study is like a detailed inspection report from a team of engineers in Cali, Colombia. They wanted to see how the power plants (hearts) of adults with Sickle Cell Disease were holding up. Since most previous reports came from the US, Europe, or Africa, the researchers wanted to know: What does the heart look like in a Latin American city with a high population of Afro-descendants?

Here is the breakdown of their findings, using simple analogies:

1. The Inspection Team and the City

The researchers looked at 57 adults (mostly in their early 20s) at a major hospital in Cali. Think of this as a "spot check" of the city's infrastructure. They used an ultrasound machine (echocardiogram), which is like a high-tech sonar that lets doctors see inside the heart without cutting anyone open. It's cheap, safe, and works like a flashlight in a dark room.

2. The Good News: The Engine is Still Running Strong

Surprisingly, for most of these young adults, the "engine" was in great shape.

• The Pump: The main pump (Left Ventricle) was strong and pumping efficiently, just like a healthy car engine.
• The Shape: Most hearts were the right size and shape. They hadn't stretched out or thickened up too much yet.
• The Flexibility: The heart muscle was still flexible, able to relax and fill up with blood easily.

Why is this good? It suggests that because these patients are relatively young and many are taking a medication called Hydroxyurea (which acts like a "traffic controller" to keep the sickle trucks from getting stuck), their hearts haven't been worn down as much as they might have been in older studies.

3. The Warning Sign: The "Pressure Valve" Issue

However, the engineers found a specific problem in about one-third of the patients.

Imagine the heart has a pressure valve (the right side) that pushes blood toward the lungs to get oxygen. In these patients, the pressure in that valve was higher than it should be.

• The Clue: The ultrasound showed that blood was shooting through this valve too fast (like water from a hose turned up to maximum pressure).
• The Meaning: This is a red flag for Pulmonary Hypertension (high blood pressure in the lungs). It's like the lungs are saying, "The pipes are too narrow, and the pressure is building up!"

Even though the patients didn't always feel sick, this "pressure spike" is a silent warning. If ignored, it could eventually wear out the engine.

4. The Big Takeaway: Check the Engine Early

The most important lesson from this study is about prevention.

In the past, doctors might have waited until a patient felt short of breath or tired before checking their heart. But this study says: "Don't wait for the smoke!"

Because the ultrasound is like a cheap, easy-to-use flashlight, doctors in Colombia (and other places with limited resources) should use it routinely to check the heart's pressure.

• If the pressure is normal: Keep doing what you're doing.
• If the pressure is high: It's a signal to step up treatment before the patient gets sick. It's like fixing a leak in a pipe before the whole house floods.

Summary

This study is a hopeful but cautious report.

• Hopeful: The hearts of these young Colombian adults are surprisingly strong and healthy, likely thanks to modern treatments.
• Cautious: About 30% of them have a hidden "pressure problem" in their lungs that needs attention.
• The Solution: Use simple, affordable ultrasound scans to catch these problems early, acting like a maintenance crew fixing the city's infrastructure before a major breakdown occurs.

In short: The heart is resilient, but it needs a regular "sonar check" to ensure the pressure doesn't build up to dangerous levels.

Technical Summary

1. Problem Statement

Sickle Cell Disease (SCD) is a significant global health burden, particularly in sub-Saharan Africa and Latin America. While improvements in therapy have extended patient survival, cardiopulmonary complications have become the leading cause of premature death in adults with SCD.

• The Gap: Most existing echocardiographic data on SCD originate from North America, Europe, the Middle East, or sub-Saharan Africa. There is a scarcity of data from Latin American populations, which differ in genetic background, age structure, comorbidity profiles, and access to disease-modifying therapies.
• The Specific Context: No contemporary study has systematically described the echocardiographic profile of adults with SCD in the Colombian Pacific region, a demographic with a high concentration of Afro-descendant ancestry.
• Objective: To characterize the structural, functional, and hemodynamic echocardiographic profile of adults with SCD in Cali, Colombia, to identify cardiovascular risk markers, specifically focusing on pulmonary hypertension (PH) and ventricular dysfunction.

2. Methodology

• Study Design: Observational, descriptive, cross-sectional study.
• Setting: Hospital Universitario del Valle "Evaristo García" (HUV), a tertiary referral center in Cali, Colombia.
• Timeframe: January 2022 to December 2024.
• Participants:
  • Inclusion: Adults (≥18 years) with confirmed SCD (via hemoglobin electrophoresis or DNA) and at least one complete transthoracic echocardiogram (TTE).
  • Exclusion: Complex congenital heart disease, severe valvular disease unrelated to SCD, pregnancy, insufficient image quality, or unconfirmed diagnosis.
  • Final Cohort: 57 patients (out of 669 screened).
• Data Collection: Retrospective review of electronic medical records and TTE reports.
• Echocardiographic Protocol:
  • Performed by board-certified cardiologists (Level III training).
  • Followed American Society of Echocardiography (ASE) and European Association of Cardiovascular Imaging (EACVI) guidelines.
  • Key Metrics: Left ventricular (LV) geometry, systolic function (Ejection Fraction, Global Longitudinal Strain [GLS]), diastolic function (E/A, E/e'), right ventricular (RV) function (TAPSE, S'), valvular regurgitation, and pulmonary hemodynamics (Tricuspid Regurgitation Velocity [TRV]).
• Statistical Analysis: Descriptive statistics (median/IQR or mean/SD). No multivariable modeling was performed due to sample size.

3. Key Results

Demographics and Clinical Profile:

• Median Age: 24 years (IQR 21–32); 59.6% female.
• Genotype: SS genotype was dominant (76.4%).
• Treatment: 71.4% were on hydroxyurea.
• Clinical Status: 66.1% reported a vaso-occlusive crisis in the prior 30 days; 84% were NYHA Class I (asymptomatic).
• Biomarkers: Median Hemoglobin 10.2 g/dL; Median NT-proBNP 491 pg/mL.

Cardiac Structure and Function:

• LV Geometry: Mostly normal (42.1%). Concentric remodeling (24.6%), concentric hypertrophy (21.1%), and eccentric hypertrophy (12.3%) were present but less prevalent than in older cohorts.
• Systolic Function: Preserved. Median LVEF was 63%; Mean GLS was −18.9% (within normal limits).
• RV Function: Preserved. Mean TAPSE was 25.4 mm.
• Diastolic Function: Normal in 71.4% of patients. Grade I dysfunction in 21.4%; Grade II in 7.1%. No Grade III dysfunction observed.
• Valvular Disease: Predominantly mild. Mild tricuspid regurgitation was most common (≈86%).

Pulmonary Hemodynamics (Critical Finding):

• TRV Distribution:
  • Median TRV: 2.4 m/s.
  • TRV >2.5 m/s: Found in 29.8% of patients (intermediate probability of PH).
  • TRV >3.0 m/s: Found in 10.5% of patients (high probability of PH).
• Estimated Pulmonary Artery Systolic Pressure: Median 26.7 mmHg.

4. Key Contributions

1. First Regional Characterization: This is the first systematic echocardiographic study of adult SCD patients in the Colombian Pacific, filling a significant geographic and demographic data gap.
2. Validation of Risk Markers in LMICs: The study confirms that despite a younger cohort and high hydroxyurea usage, the burden of pulmonary hypertension risk (indicated by elevated TRV) is comparable to high-income cohorts (e.g., French and North American studies).
3. Feasibility of Routine Screening: Demonstrates that TTE is a viable, accessible, and non-invasive tool for early cardiovascular risk stratification in low- and middle-income settings (LMICs) where advanced imaging (like MRI or right heart catheterization) is less available.
4. Impact of Hydroxyurea: The preservation of LV mass and geometry in this cohort (compared to older cohorts with more remodeling) suggests a potential protective effect of high hydroxyurea adherence (71.4%) against adverse cardiac remodeling.

5. Significance and Implications

• Clinical Practice: The finding that nearly one-third of asymptomatic or mildly symptomatic young adults have echocardiographic signs suggestive of pulmonary hypertension underscores the need for routine TTE screening in SCD management, even in young patients.
• Public Health: In LMICs, TTE should be utilized as a primary triage tool. Patients with TRV >2.5 m/s should be flagged for further evaluation (potentially right heart catheterization) and intensification of disease-modifying therapy (e.g., optimizing hydroxyurea) before the onset of overt heart failure or symptomatic deterioration.
• Future Research: The study highlights the need for prospective, multicenter studies with longitudinal follow-up and right heart catheterization to confirm the prevalence of PH and correlate echocardiographic findings with hard clinical outcomes (mortality, hospitalization) in Latin American populations.

Limitations Noted: Retrospective single-center design, lack of a healthy local control group, small sample size (n=57), and absence of confirmatory right heart catheterization for pulmonary hypertension.