From a historical perspective, it should be noted that percutaneous procedures would not have been possible to pursue without the tremendous efforts of Grüntzig's predecessors. After the French physiologist Claude Bernard recorded intracardiac pressures in animals and introduced the term cardiac catheterization in 1844, it took many years before human cardiac catheterization was document- ed for the first time. In 1929, the German physician Werner Forssmann, who was searching for the most efficacious routes of drug delivery and who did not quite adhere to the institutional rules, succeeded in puncturing the antecubital vein and advancing a urethral catheter to the right atrium of his own heart. Admiration of his courageous endeavors was renowned in 1956 when Nobel Prize candidates Andre F. Cournand and Dickinson W. Richards proposed that the committee include Forssmann, who actually inspired their work, as the third nominee. Ironically, after Forssmann's death, the clinic, which had fired the intern Forssmann for this experiment and invalidated his medical license, was named after him in 1979. 

Despite the lack of recognition, further evolution of the Nobel Prize-winning idea of heart catheterization translated into widespread use of this procedure for diagnostic assessments. However, the increase in the precision of catheterization using selective coronary imaging has helped elaborate surgical and interventional treatment strategies. Since 1958, the American cardiologist Frank Mason Sones, Chief of Pediatric Cardiology at the Cleveland Clinic, started performing selective imaging of the coronary arteries. During diagnostic ventriculo- and aortography in a 29-year-old patient with rheumatic disease, Sones inadvertently visualized the right coronary artery by injecting 30 mL of contrast medium into the aorta. As it appeared to be safe in terms of life-threatening arrhythmias, this play of chance inspired further clinical investigations. In 1966, Sones et al published data summarizing the correlates of angiography with the clinical data from 1 000 patients. The tedious work of Sones paved the way for his colleague, surgeon Rene Favaloro, to invent coronary artery bypass grafting, which was successfully performed at the Cleveland Clinic in 1967. Since then, Sones has performed more than 10 000 catheterizations, mainly using a brachial approach, which, due to local bleeding complications, may not have been the optimal approach in all cases. 

The introduction of the safe artery catheterization technique by the Swedish ra- diologist Sven Ivar Seldinger in 1953 and the fashioning of preshaped catheters by Melvin Paul Judkins in 1967 led to further widespread use and ease of the manipulations. These remarkable techniques have been used in millions of procedures and they continue to be used today.

Searching for less invasive alternatives for the management of atherosclerotic disease and following the concept of remodeling, which was introduced in 1964 by the radiologist Charles Dotter, Andreas Grüntzig worked on better options for lesion dilatation. Experimental procedures utilized a home-assembled, single-lumen, preshaped dilatation catheter with a "sausage-shaped distensible segment (balloon) at the tip.”3 Thus, the first-in-man percutaneous transluminal coronary angioplasty was preceded by performing a relatively large series of peripheral arterial lesion dilatations to gain experience. In February 1974, Grüntzig started
with the treatment of superficial femoral artery stenosis, and, in 1977, he reported promising follow-up results from 250 patients with periphery artery disease, showing >70% patency of the iliac and femoropopliteal arteries 2 years after the procedure.

Extensive animal studies on intraoperative coronary artery balloon dilatations translated into uneventful percutaneous transluminal coronary angioplasties, which offered an alternative to coronary artery bypass grafting to 5 male patients with refractory angina and severe stenotic coronary lesions.3 These endeavors were supported by the surgeon Ake Senning, who was Head of the Heart Surgery Clinic at the Zurich University Hospital and who coauthored the publication that came out a year later. The results of a somewhat larger clinical study (n=50) claimed a procedural success rate of 64% and reduced the need for emergency bypass surgery by 10%.4 Therefore, based on the analysis of their experiences, as the only available data at the time, Grüntzig considered “patients with the single-vessel disease… to be the most suitable for the procedure” and hypothesized that “only 10 - 15 percent of candidates for bypass surgery have lesions suitable for this procedure.”

The limitations and non encouraging long-term results of percutaneous translนminal coronary angioplasty appeared to be constraints to the rapid recognition of the clinical value of this technique. Further investigations focused on protecting the vessel from restenosis and thrombosis. Cesare Gianturco, an Italian radiologist, presented Andreas Grüntzig's z-shaped circular wire, and he was the first to use the term "stent." There were several physicians working on the concept of providing support to the arterial wall, and so a new era began on March 28, 1986. which was marked by Jacques Puel performing a "double-helix" "Wallstent" met- al device implantation. Shortly after, in June 1986, Ulrich Sigwart expanded the indications for coronary interventions by performing rescue stenting of an occlusive left anterior descending coronary artery proximal dissection. Then, the Institutional Review Board approved coronary stenting for abrupt closure after percutaneous transluminal coronary angioplasty, restenosis, saphenous vein graft stenosis, and periphery artery stenosis.

The initial enthusiasm with bare-metal stent implantations was tempered by the increasing number of stent thrombosis, which resulted in an extensive search for newer antithrombotic agents and efficacious medical treatment regimens. Dual antiplatelet therapy appeared to be a successful measure to prevent in-stent thrombosis; it was validated in 1996 by the French cardiologist Marie-Claude Morice. As the management of acute thrombotic events advanced, questions were raised concerning the proper management of potentially fatal acute coronary syndromes. The usefulness of PCI for treating patients with acute coronary syndromes was highly debated; however, it received recognition after the PAMI trial, which demonstrated the efficacy of primary PCI vs on-site thrombolysis in selected patient populations. Currently, there is no doubt that PCI is an urgent lifesaving procedure in patients with acute coronary syndromes.

However, despite a better management of thrombotic issues via prescription of dual antiplatelet therapy and optimal stent apposition and deployment, stent restenosis remained the main issue until the discovery of a way to manage the proliferative phase of neointimal hyperplasia and constrictive remodeling. In 1996, Robert Falotico identified sirolimus, or rapamycin, a failed antibiotic, but potent inhibitor of smooth cell proliferation and migration, as an appropriate agent for stent coating. Going from bench to bedside, the randomized RAVEL trial elucidated the superiority of sirolimus-coated stents over bare-metal stents for reducing restenosis, thus opening a new era for a wider use of coronary stenting.

Although early in-stent restenosis was sufficiently managed by first- and second-generation drug-eluting stents, later in-stent stenosis development became a concern. Very late stent restenosis may result from impaired artery physiology, chronic endothelial degeneration, and a local inflammatory response to the coating polymer. Therefore, the idea of successfully placing self-degrading, bioresorbable stents was developed. This paradigm shift in interventional cardiology, along with proper medical therapies, offers a potential opportunity to restore vascular physiology.

Numerous pivotal changes in the use of interventional procedures have occurred during the last decades. Due to accumulated evidence. eg, SYNTAX trial data, broader alternatives to surgical revascularization have been offered, such as left main coronary artery stenting in patients with an acceptable anatomy., PCIs have dramatically changed the scope of surgical operations. In patients with structural heart disease, such as valvular disease, and congenital heart defects, the number of interventions and the variety of commercially available devices is steadily rising. Today, thousands of transcatheter aortic valve replacements have been performed worldwide, affecting the survival in elderly patients; the annual number of these procedures exceeded the number of conventional surgical aortic valve replacements in some European countries.

Although the role of PCI could not be overestimated, another “back to the future” event has occurred recently. After the ORBITA trial outcome results, we are returning to the discussion of whether stable patients with coronary heart disease should undergo PCI or merely continue to take optimized medical therapy. In many ways, the results of this first placebo-controlled study in PCI patients receiving optimal medical therapy may not substantially affect the number of PCIs performed in patients with stable angina, but it brings into focus the importance and efficacy of medical therapy in patients with stable coronary artery disease. 

Summarizing experiences gained in the evolving area of cardiology and looking back at the tremendous efforts of outstanding professionals, such as Andeas Grüntzig, Charles Dotter, Frank Mason Sones, Sven Ival Seldinger, Melvin Paul Judkins, and many others, it is now evident how powerful thought and endeavor could be to protect human life.