Description
Pulmonary Hypertension, Cor Pulmonale, and Miscellaneous Vascular Conditions: A Comprehensive Clinical Compendium and Therapeutic Guide
In the silence of medical knowledge, where science meets human destiny, the understanding of pulmonary hypertension is born – a condition that requires not only the precision of the scalpel and the accuracy of the formula, but also the kindness of the healer. As Asclepius, I offer you this analysis, guided by the pursuit of well-being and balance, transforming complex pathophysiology into accessible knowledge for those who have dedicated their lives to the art of healing.
Definition and fundamental concepts
Pulmonary hypertension (PH) is not just a diagnosis, but a complex hemodynamic condition that reflects changes in the pulmonary vasculature. Historically defined as mean pulmonary artery pressure ( mPAP ) ≥25 mmHg, modern science, reflected in the 2022 ESC/ERS guidelines, has refined this threshold. Today, PH is defined hemodynamically as mPAP >20 mmHg at rest, measured by right heart catheterization. This reduction in the threshold is the result of meta-analyses of healthy subjects and evidence that even modest increases in pressure (between 21 and 24 mmHg) carry an increased risk of mortality and disease progression, especially in patients with systemic sclerosis.
The normal pulmonary circulation is a low-resistance, high-capacity system capable of accommodating the entire cardiac output at pressures that are one-fifth those in the systemic circulation. This balance is maintained by dilation of existing vessels and recruitment of unused capillaries. When this mechanism fails, vascular remodeling occurs, which is the basis of pathology.
Hemodynamic classification
For a proper understanding of PH, it is critical to distinguish between precapillary and postcapillary forms, as the therapeutic approach is fundamentally different.
| Hemodynamic category | mPAP (mmHg) | PAWP (mmHg) | PVR (Wood Units) |
| Precapillary PH | >20 | ≤15 | >2 |
| Isolated postcapillary PH (IpcPH) | >20 | >15 | ≤2 |
| Combined pre- and postcapillary PH (CpcPH) | >20 | >15 | >2 |
Precapillary PH is characteristic of groups 1, 3, 4 and some conditions from WHO group 5, while postcapillary PH is the result of left heart diseases (group 2).
Epidemiology and global burden
Pulmonary hypertension is a global health problem, affecting approximately 1% of the world’s population, with the incidence increasing to 10% in people over 65 years of age. Although age-standardized prevalence rates have shown a slight decline in some regions in recent decades, the absolute number of cases is increasing due to the aging of the population.
In 2021, there were an estimated 191,808 prevalent cases of pulmonary arterial hypertension (PAH) worldwide, with women being affected more often than men (ratio 1.62:1). The economic burden is significant, with the average cost of hospitalization per patient with PAH increasing from $82,000 in 2016 to $125,000 in 2020 .
WHO clinical classification
The WHO classification divides PH into five groups based on similar pathophysiology, clinical presentation, and therapeutic strategies.
Group 1: Pulmonary arterial hypertension (PAH)
This group includes conditions characterized by progressive remodeling of the small pulmonary arteries. It encompasses idiopathic PAH, hereditary PAH (associated with mutations in the BMPR 2 or EIF 2 AK 4 genes), PAH induced by drugs and toxins (e.g., anorexigenics, methamphetamines), and PAH associated with systemic diseases such as connective tissue diseases, HIV infection, portal hypertension, and congenital heart defects.
Group 2: PH due to left heart disease
This is the most common form of PH. It is due to increased pressure in the left atrium and pulmonary veins as a result of left ventricular systolic or diastolic dysfunction, or valvular defects (mitral stenosis/regurgitation).
Group 3: PH due to lung disease and/or hypoxia
Includes PH resulting from chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD), sleep-disordered breathing (sleep apnea), and chronic exposure to high altitude.
Group 4: PH due to pulmonary arterial obstructions
The main representative is chronic thromboembolic pulmonary hypertension (CTEPH), which develops after an unresolved pulmonary embolism. This also includes other obstructions such as angiosarcoma or arteritis.
Group 5: PH with unclear and/or multifactorial mechanisms
Covers systemic diseases (sarcoidosis), hematological disorders (sickle cell anemia), metabolic diseases (Gaucher disease, thyroid disorders) and chronic renal failure.
Pathophysiology (By Harrison standards)
The pathophysiology of PH is a complex process of vascular remodeling, endothelial dysfunction, and metabolic changes. In the normal pulmonary circulation, the endothelium produces vasodilators (nitric oxide, prostacyclin) and vasoconstrictors (endothelin-1) in a delicate balance. In PH, this balance is disrupted.
Mechanisms of vascular damage
- Endothelial dysfunction: The expression of endothelial nitric oxide synthase (eNOS) and prostacyclin synthase is reduced. At the same time, the levels of endothelin-1, a potent vasoconstrictor and mitogen, are increased.
- Vascular remodeling: Proliferation of smooth muscle cells in the media, intimal thickening, and fibrosis lead to narrowing and obliteration of the vessels. In advanced stages, plexiform lesions form – complex vascular structures resulting from disorganized angiogenesis.
- In situ thrombosis: Slowed blood flow and endothelial damage stimulate local thrombus formation, which further increases vascular resistance.
- Inflammation: Infiltration of inflammatory cells and release of cytokines play a key role in the progression of vascular damage.
Right ventricular response (Cor Pulmonale)
PVR ) increases , the RV initially hypertrophies to maintain cardiac output. As the disease progresses, the RV becomes dilated, leading to right ventricular failure and a decrease in systemic cardiac output. This condition of cardiac involvement secondary to pulmonary pathology is called cor pulmonale .
Clinical manifestation
The clinical picture of PH is often nonspecific, leading to a delay in diagnosis of an average of 2 years from the onset of the first symptoms.
Symptoms
- Dyspnea on exertion: The most common early symptom, often overlooked or attributed to poor fitness.
- Fatigue and weakness: Due to the heart’s inability to increase output under stress.
- Syncope (loss of consciousness): Often occurs during exertion and is a sign of severe RV dysfunction and a poor prognostic sign.
- Chest pain: May resemble angina due to RV ischemia or pulmonary artery distension.
- Edema and ascites: Late signs of right-sided heart failure.
- Hoarseness of voice (Ortner syndrome): Due to compression of the recurrent laryngeal nerve by the dilated pulmonary artery.
Diagnostics
The diagnostic approach requires a high index of clinical suspicion and a stepwise algorithm.
Diagnostic criteria and algorithm
- Clinical suspicion: Patient with unexplained dyspnea on exertion or signs of right-sided heart failure.
- Echocardiography Screening: Used to assess the likelihood of PH by measuring the peak tricuspid regurgitation velocity ( TRV ).
- Non-invasive tests: ECG, chest X-ray, functional respiratory study, V/Q scan (critical for excluding CTEPH).
- Confirmation with right heart catheterization: Gold standard for making a definitive diagnosis and determining hemodynamic type.
Physical Examination: Clinical Findings
During the examination, the doctor may find:
- Accentuated second heart sound ( P 2 ) : A key sign of elevated pulmonary artery pressure.
- Right ventricular impulse: Palpated along the left sternal border.
- Tricuspid regurgitation murmur: Holosystolic murmur that intensifies with inspiration (Rivero-Carvalho sign).
- Dilated jugular veins: With a pronounced ‘a’ wave.
- Hepatomegaly, pulsatile liver and peripheral edema: In right ventricular failure.
Laboratory tests
- Natriuretic peptides (BNP, NT-proBNP): Markers of myocardial stretch in CKD. Their levels correlate with disease severity and are key for monitoring.
- Blood gases: May show hypoxemia and hypocapnia (resulting from hyperventilation).
- Autoimmune tests: To rule out connective tissue diseases.
- HIV test and liver enzymes: To evaluate associated causes.
Instrumental and imaging studies
- Electrocardiogram (ECG): May show right-sided type, right ventricular hypertrophy, right bundle branch block, and dilated right atrium (P-pulmonale).
- Chest X-ray: Dilated central pulmonary arteries and “peripheral thinning” ( pruning) of the vessels.
- Computed tomography (CT): Assessment of parenchyma, pulmonary artery diameter ( ≥29 mm is suspicious for PH) and exclusion of thromboembolism.
- V/Q scan: Method of choice for screening for CTEPH. A normal scan virtually excludes CTEPH.
- Cardiac MRI: Gold standard for assessing RV volumes and function.
Differential diagnosis (French’s Index approach)
Differential diagnosis should be performed systematically, ranking diseases by probability and severity, according to the analytical approach of French’s Index.
Dyspnea (Shortness of breath)
| Probability | Pathology | Differentiating features |
| High | Left-sided heart failure | Edema, orthopnea, echocardiographic finding of LV dysfunction. |
| High | COPD or Asthma | Chest wheezing, smoking, obstructive type of FID. |
| Medium | Pulmonary hypertension | Absence of pulmonary disease, accentuated P 2 , right-sided ECG pattern. |
| Medium | Pulmonary embolism (acute) | Sudden onset, pleural pain, risk factors for TEB. |
| Low | Severe anemia | Pallor, low hemoglobin. |
| Low | Psychogenic shortness of breath | Panic attacks, normal saturation. |
Syncope (Loss of consciousness)
| Probability | Pathology | Differentiating features |
| High | Vasovagal syncope | Prodromes (nausea, sweating), provocation by pain/emotion. |
| Medium | Arrhythmias | Sudden onset, palpitations, ECG changes. |
| Low/Heavy | Obstructive syncope (PH, Aortic stenosis) | Always with physical exertion; requires urgent evaluation. |
Therapy
The treatment of PH is complex and requires a team of specialists. “First, do no harm” is the guiding principle, especially when choosing vasodilators.
Pharmacotherapeutic targets
The main goals are to improve functional capacity (WHO FC), increase quality of life, reduce pulmonary pressure and resistance, and improve survival.
Non-pharmacological and holistic therapies
- Diet: Anti-inflammatory diet (Mediterranean type) with an emphasis on omega-3 fatty acids and low sodium intake to control swelling.
- Magnesium: Ensure adequate intake (6 mg/kg daily) to maintain vascular tone.
- Breathing techniques: Controlled breathing exercises can reduce feelings of dyspnea and stress.
- Adapted physical activity: Light walking and rehabilitation under medical supervision are helpful, but heavy physical exertion should be avoided.
Classical pharmacotherapy
Treatment is based on three main pathogenetic pathways.
- Nitric oxide (NO) pathway
- PDE-5 inhibitors: Sildenafil (20 mg 3 times daily) or Tadalafil (40 mg once daily). These increase cGMP levels, leading to vasodilation.
- sGC stimulators: Riociguat (0.5–2.5 mg 3 times daily). Directly stimulates soluble guanylate cyclase.
- Endothelin pathway
- Endothelin receptor antagonists (ERAs): Bosentan (125 mg twice daily), Ambrisentan (5–10 mg once daily), Macitentan (10 mg once daily). Reduce vasoconstriction and vascular proliferation.
- Prostacyclin pathway
- Prostacyclin analogues: Epoprostenol (intravenous, gold standard in severe cases), Iloprost (inhaled), Treprostinil (subcutaneous or intravenous).
- Prostacyclin receptor agonists: Selexipag (200–1600 μg twice daily).
Calcium channel blockers (CCBs)
They are used only in a small group of patients (5-10%) who show a positive response to a vasoreactivity test during catheterization. Examples: Nifedipine (30-120 mg/day), Diltiazem (120-480 mg/day).
Interactions and Warnings
Doctors and patients should be extremely careful when combining conventional medications with herbs and supplements.
- PDE-5 inhibitors + Nitrates: Strictly contraindicated due to risk of fatal hypotension.
- John’s Wort: May induce CYP3A4 enzymes and reduce plasma levels of Sildenafil and Bosentan, rendering the treatment ineffective.
- Ginkgo Biloba: Has an antiplatelet effect and may increase the risk of bleeding in patients on anticoagulants (often used in CHTEPH).
- Licorice: May cause fluid retention and worsen heart failure, as well as reduce the effect of diuretics.
- Green tea: In large quantities, it may interfere with the metabolism of some calcium antagonists and beta-blockers.
Conclusion
Pulmonary hypertension is a serious challenge that requires a holistic view and precise therapy. As Asclepius, I remind you that each body is unique and treatment must be adapted to the individual needs of the person. My analysis is indicative and consultative. In any doubt about this condition, ethical and safe behavior requires examination and follow-up by a physical specialist (cardiologist or pulmonologist) in a specialized center for pulmonary hypertension. May the path to health be guided by knowledge, patience and compassion.
